diff --git a/configure.ac b/configure.ac
index 4865ca4dc..85ba939a8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1803,6 +1803,7 @@ if test "x$enable_gcc_warnings_advisory" != "xno"; then
      -Wmissing-noreturn
      -Wmissing-selector-name
      -Wmissing-sysroot
+     -Wmissing-variable-declarations
      -Wmodule-conflict
      -Wnested-anon-types
      -Wnewline-eof
diff --git a/src/common/compat_libevent.c b/src/common/compat_libevent.c
index cc5888375..96fcec54d 100644
--- a/src/common/compat_libevent.c
+++ b/src/common/compat_libevent.c
@@ -125,7 +125,7 @@ tor_event_free(struct event *ev)
 #endif
 
 /** Global event base for use by the main thread. */
-struct event_base *the_event_base = NULL;
+static struct event_base *the_event_base = NULL;
 
 /* This is what passes for version detection on OSX.  We set
  * MACOSX_KQUEUE_IS_BROKEN to true iff we're on a version of OSX before
diff --git a/src/common/crypto.h b/src/common/crypto.h
index ff38cca0d..f8fb0daa8 100644
--- a/src/common/crypto.h
+++ b/src/common/crypto.h
@@ -319,6 +319,11 @@ void crypto_add_spaces_to_fp(char *out, size_t outlen, const char *in);
 #ifdef CRYPTO_PRIVATE
 STATIC int crypto_force_rand_ssleay(void);
 STATIC int crypto_strongest_rand_raw(uint8_t *out, size_t out_len);
+
+#ifdef TOR_UNIT_TESTS
+extern int break_strongest_rng_syscall;
+extern int break_strongest_rng_fallback;
+#endif
 #endif
 
 #endif
diff --git a/src/common/log.c b/src/common/log.c
index 6c387c624..e948ccfa0 100644
--- a/src/common/log.c
+++ b/src/common/log.c
@@ -270,7 +270,7 @@ log_tor_version(logfile_t *lf, int reset)
   return 0;
 }
 
-const char bug_suffix[] = " (on Tor " VERSION
+static const char bug_suffix[] = " (on Tor " VERSION
 #ifndef _MSC_VER
   " "
 #include "micro-revision.i"
diff --git a/src/common/tortls.c b/src/common/tortls.c
index 252da6295..1cb6ca877 100644
--- a/src/common/tortls.c
+++ b/src/common/tortls.c
@@ -562,7 +562,7 @@ MOCK_IMPL(STATIC X509 *,
 
 /** List of ciphers that servers should select from when we actually have
  * our choice of what cipher to use. */
-const char UNRESTRICTED_SERVER_CIPHER_LIST[] =
+static const char UNRESTRICTED_SERVER_CIPHER_LIST[] =
   /* This list is autogenerated with the gen_server_ciphers.py script;
    * don't hand-edit it. */
 #ifdef TLS1_TXT_ECDHE_RSA_WITH_AES_256_GCM_SHA384
diff --git a/src/common/tortls.h b/src/common/tortls.h
index 1a59c67df..b6ab2ec8f 100644
--- a/src/common/tortls.h
+++ b/src/common/tortls.h
@@ -164,8 +164,18 @@ STATIC int tor_tls_context_init_one(tor_tls_context_t **ppcontext,
                                     int is_client);
 STATIC void tls_log_errors(tor_tls_t *tls, int severity, int domain,
                            const char *doing);
+
+#ifdef TOR_UNIT_TESTS
+extern int tor_tls_object_ex_data_index;
+extern tor_tls_context_t *server_tls_context;
+extern tor_tls_context_t *client_tls_context;
+extern uint16_t v2_cipher_list[];
+extern uint64_t total_bytes_written_over_tls;
+extern uint64_t total_bytes_written_by_tls;
 #endif
 
+#endif /* endif TORTLS_PRIVATE */
+
 const char *tor_tls_err_to_string(int err);
 void tor_tls_get_state_description(tor_tls_t *tls, char *buf, size_t sz);
 
diff --git a/src/ext/ed25519/donna/ed25519-donna-batchverify.h b/src/ext/ed25519/donna/ed25519-donna-batchverify.h
index 43c4923b3..7c64cce78 100644
--- a/src/ext/ed25519/donna/ed25519-donna-batchverify.h
+++ b/src/ext/ed25519/donna/ed25519-donna-batchverify.h
@@ -188,7 +188,7 @@ ge25519_multi_scalarmult_vartime(ge25519 *r, batch_heap *heap, size_t count) {
 }
 
 /* not actually used for anything other than testing */
-unsigned char batch_point_buffer[3][32];
+static unsigned char batch_point_buffer[3][32];
 
 static int
 ge25519_is_neutral_vartime(const ge25519 *p) {
diff --git a/src/ext/tinytest.c b/src/ext/tinytest.c
index f6baeeb9a..3fb1b39c7 100644
--- a/src/ext/tinytest.c
+++ b/src/ext/tinytest.c
@@ -69,15 +69,16 @@ static int n_skipped = 0; /**< Number of tests that have been skipped. */
 static int opt_forked = 0; /**< True iff we're called from inside a win32 fork*/
 static int opt_nofork = 0; /**< Suppress calls to fork() for debugging. */
 static int opt_verbosity = 1; /**< -==quiet,0==terse,1==normal,2==verbose */
-const char *verbosity_flag = "";
+static const char *verbosity_flag = "";
 
-const struct testlist_alias_t *cfg_aliases=NULL;
+static const struct testlist_alias_t *cfg_aliases=NULL;
 
 enum outcome { SKIP=2, OK=1, FAIL=0 };
 static enum outcome cur_test_outcome = 0;
-const char *cur_test_prefix = NULL; /**< prefix of the current test group */
+/** prefix of the current test group */
+static const char *cur_test_prefix = NULL;
 /** Name of the current test, if we haven't logged is yet. Used for --quiet */
-const char *cur_test_name = NULL;
+static const char *cur_test_name = NULL;
 
 #ifdef _WIN32
 /* Copy of argv[0] for win32. */
diff --git a/src/or/channel.c b/src/or/channel.c
index 78a2fb9ab..87fa72108 100644
--- a/src/or/channel.c
+++ b/src/or/channel.c
@@ -122,7 +122,7 @@ STATIC uint64_t estimated_total_queue_size = 0;
  * If more than one channel exists, follow the next_with_same_id pointer
  * as a linked list.
  */
-HT_HEAD(channel_idmap, channel_idmap_entry_s) channel_identity_map =
+static HT_HEAD(channel_idmap, channel_idmap_entry_s) channel_identity_map =
   HT_INITIALIZER();
 
 typedef struct channel_idmap_entry_s {
diff --git a/src/or/channel.h b/src/or/channel.h
index a8c337e10..78e1b7101 100644
--- a/src/or/channel.h
+++ b/src/or/channel.h
@@ -469,6 +469,10 @@ void channel_notify_flushed(channel_t *chan);
 /* Handle stuff we need to do on open like notifying circuits */
 void channel_do_open_actions(channel_t *chan);
 
+#ifdef TOR_UNIT_TESTS
+extern uint64_t estimated_total_queue_size;
+#endif
+
 #endif
 
 /* Helper functions to perform operations on channels */
diff --git a/src/or/channeltls.c b/src/or/channeltls.c
index 5833b2ae6..2bb88dd50 100644
--- a/src/or/channeltls.c
+++ b/src/or/channeltls.c
@@ -22,6 +22,7 @@
 #include "channeltls.h"
 #include "circuitmux.h"
 #include "circuitmux_ewma.h"
+#include "command.h"
 #include "config.h"
 #include "connection.h"
 #include "connection_or.h"
@@ -51,7 +52,7 @@ uint64_t stats_n_authenticate_cells_processed = 0;
 uint64_t stats_n_authorize_cells_processed = 0;
 
 /** Active listener, if any */
-channel_listener_t *channel_tls_listener = NULL;
+static channel_listener_t *channel_tls_listener = NULL;
 
 /* channel_tls_t method declarations */
 
diff --git a/src/or/channeltls.h b/src/or/channeltls.h
index a4d9c7a09..8b5863a46 100644
--- a/src/or/channeltls.h
+++ b/src/or/channeltls.h
@@ -52,6 +52,14 @@ void channel_tls_update_marks(or_connection_t *conn);
 /* Cleanup at shutdown */
 void channel_tls_free_all(void);
 
+extern uint64_t stats_n_authorize_cells_processed;
+extern uint64_t stats_n_authenticate_cells_processed;
+extern uint64_t stats_n_versions_cells_processed;
+extern uint64_t stats_n_netinfo_cells_processed;
+extern uint64_t stats_n_vpadding_cells_processed;
+extern uint64_t stats_n_certs_cells_processed;
+extern uint64_t stats_n_auth_challenge_cells_processed;
+
 #ifdef CHANNELTLS_PRIVATE
 STATIC void channel_tls_process_certs_cell(var_cell_t *cell,
                                            channel_tls_t *tlschan);
diff --git a/src/or/circuitlist.c b/src/or/circuitlist.c
index 1efb7ef4d..d2ba7d478 100644
--- a/src/or/circuitlist.c
+++ b/src/or/circuitlist.c
@@ -109,7 +109,7 @@ HT_GENERATE2(chan_circid_map, chan_circid_circuit_map_t, node,
  * used to improve performance when many cells arrive in a row from the
  * same circuit.
  */
-chan_circid_circuit_map_t *_last_circid_chan_ent = NULL;
+static chan_circid_circuit_map_t *_last_circid_chan_ent = NULL;
 
 /** Implementation helper for circuit_set_{p,n}_circid_channel: A circuit ID
  * and/or channel for circ has just changed from <b>old_chan, old_id</b>
diff --git a/src/or/circuitmux_ewma.h b/src/or/circuitmux_ewma.h
index 58aac1e19..a7b8961ac 100644
--- a/src/or/circuitmux_ewma.h
+++ b/src/or/circuitmux_ewma.h
@@ -12,13 +12,8 @@
 #include "or.h"
 #include "circuitmux.h"
 
-/* Everything but circuitmux_ewma.c should see this extern */
-#ifndef TOR_CIRCUITMUX_EWMA_C_
-
 extern circuitmux_policy_t ewma_policy;
 
-#endif /* !(TOR_CIRCUITMUX_EWMA_C_) */
-
 /* Externally visible EWMA functions */
 int cell_ewma_enabled(void);
 unsigned int cell_ewma_get_tick(void);
diff --git a/src/or/config.c b/src/or/config.c
index ca1e17c4a..a863fdb55 100644
--- a/src/or/config.c
+++ b/src/or/config.c
@@ -65,9 +65,6 @@
 #include <systemd/sd-daemon.h>
 #endif
 
-/* From main.c */
-extern int quiet_level;
-
 /* Prefix used to indicate a Unix socket in a FooPort configuration. */
 static const char unix_socket_prefix[] = "unix:";
 
diff --git a/src/or/connection.c b/src/or/connection.c
index 86ed2fbcc..f713bbbe6 100644
--- a/src/or/connection.c
+++ b/src/or/connection.c
@@ -2697,8 +2697,6 @@ connection_is_rate_limited(connection_t *conn)
 #ifdef USE_BUFFEREVENTS
 static struct bufferevent_rate_limit_group *global_rate_limit = NULL;
 #else
-extern int global_read_bucket, global_write_bucket;
-extern int global_relayed_read_bucket, global_relayed_write_bucket;
 
 /** Did either global write bucket run dry last second? If so,
  * we are likely to run dry again this second, so be stingy with the
diff --git a/src/or/dirserv.c b/src/or/dirserv.c
index d1ea5dffd..80c73501c 100644
--- a/src/or/dirserv.c
+++ b/src/or/dirserv.c
@@ -19,6 +19,7 @@
 #include "dirvote.h"
 #include "hibernate.h"
 #include "keypin.h"
+#include "main.h"
 #include "microdesc.h"
 #include "networkstatus.h"
 #include "nodelist.h"
@@ -44,10 +45,6 @@
  * directory authorities. */
 #define MAX_UNTRUSTED_NETWORKSTATUSES 16
 
-extern time_t time_of_process_start; /* from main.c */
-
-extern long stats_n_seconds_working; /* from main.c */
-
 /** Total number of routers with measured bandwidth; this is set by
  * dirserv_count_measured_bws() before the loop in
  * dirserv_generate_networkstatus_vote_obj() and checked by
diff --git a/src/or/hibernate.c b/src/or/hibernate.c
index 3666abbcf..209aae01c 100644
--- a/src/or/hibernate.c
+++ b/src/or/hibernate.c
@@ -34,8 +34,6 @@ hibernating, phase 2:
 #include "router.h"
 #include "statefile.h"
 
-extern long stats_n_seconds_working; /* published uptime */
-
 /** Are we currently awake, asleep, running out of bandwidth, or shutting
  * down? */
 static hibernate_state_t hibernate_state = HIBERNATE_STATE_INITIAL;
diff --git a/src/or/main.c b/src/or/main.c
index 1b161336c..77d9f3ff9 100644
--- a/src/or/main.c
+++ b/src/or/main.c
@@ -2683,9 +2683,6 @@ get_uptime,(void))
   return stats_n_seconds_working;
 }
 
-extern uint64_t rephist_total_alloc;
-extern uint32_t rephist_total_num;
-
 /**
  * Write current memory usage information to the log.
  */
diff --git a/src/or/main.h b/src/or/main.h
index ad865b812..31a22de42 100644
--- a/src/or/main.h
+++ b/src/or/main.h
@@ -75,6 +75,14 @@ int tor_main(int argc, char *argv[]);
 int do_main_loop(void);
 int tor_init(int argc, char **argv);
 
+extern time_t time_of_process_start;
+extern long stats_n_seconds_working;
+extern int quiet_level;
+extern int global_read_bucket;
+extern int global_write_bucket;
+extern int global_relayed_read_bucket;
+extern int global_relayed_write_bucket;
+
 #ifdef MAIN_PRIVATE
 STATIC void init_connection_lists(void);
 STATIC void close_closeable_connections(void);
diff --git a/src/or/onion.c b/src/or/onion.c
index 4bed7ae22..26a4f857e 100644
--- a/src/or/onion.c
+++ b/src/or/onion.c
@@ -38,7 +38,7 @@ typedef struct onion_queue_t {
 
 /** Array of queues of circuits waiting for CPU workers. An element is NULL
  * if that queue is empty.*/
-TOR_TAILQ_HEAD(onion_queue_head_t, onion_queue_t)
+static TOR_TAILQ_HEAD(onion_queue_head_t, onion_queue_t)
               ol_list[MAX_ONION_HANDSHAKE_TYPE+1] = {
   TOR_TAILQ_HEAD_INITIALIZER(ol_list[0]), /* tap */
   TOR_TAILQ_HEAD_INITIALIZER(ol_list[1]), /* fast */
diff --git a/src/or/onion_ntor.c b/src/or/onion_ntor.c
index 9f97a4cfb..33afc2789 100644
--- a/src/or/onion_ntor.c
+++ b/src/or/onion_ntor.c
@@ -47,7 +47,7 @@ typedef struct tweakset_t {
 } tweakset_t;
 
 /** The tweaks to be used with our handshake. */
-const tweakset_t proto1_tweaks = {
+static const tweakset_t proto1_tweaks = {
 #define PROTOID "ntor-curve25519-sha256-1"
 #define PROTOID_LEN 24
   PROTOID ":mac",
diff --git a/src/or/rendcache.h b/src/or/rendcache.h
index 0e8b91875..270b614c3 100644
--- a/src/or/rendcache.h
+++ b/src/or/rendcache.h
@@ -102,6 +102,13 @@ STATIC void validate_intro_point_failure(const rend_service_descriptor_t *desc,
                                         const char *service_id);
 
 STATIC void rend_cache_failure_entry_free_(void *entry);
+
+#ifdef TOR_UNIT_TESTS
+extern strmap_t *rend_cache;
+extern strmap_t *rend_cache_failure;
+extern digestmap_t *rend_cache_v2_dir;
+extern size_t rend_cache_total_allocation;
+#endif
 #endif
 
 #endif /* TOR_RENDCACHE_H */
diff --git a/src/or/rephist.h b/src/or/rephist.h
index 145da97d0..ff4810a56 100644
--- a/src/or/rephist.h
+++ b/src/or/rephist.h
@@ -112,5 +112,12 @@ void rep_hist_note_negotiated_link_proto(unsigned link_proto,
                                          int started_here);
 void rep_hist_log_link_protocol_counts(void);
 
+extern uint64_t rephist_total_alloc;
+extern uint32_t rephist_total_num;
+#ifdef TOR_UNIT_TESTS
+extern int onion_handshakes_requested[MAX_ONION_HANDSHAKE_TYPE+1];
+extern int onion_handshakes_assigned[MAX_ONION_HANDSHAKE_TYPE+1];
+#endif
+
 #endif
 
diff --git a/src/or/router.c b/src/or/router.c
index 43157a907..cfc003996 100644
--- a/src/or/router.c
+++ b/src/or/router.c
@@ -40,8 +40,6 @@
  * and uploading server descriptors, retrying OR connections.
  **/
 
-extern long stats_n_seconds_working;
-
 /************************************************************/
 
 /*****
diff --git a/src/or/scheduler.h b/src/or/scheduler.h
index 94a44a0aa..3dcfd2fac 100644
--- a/src/or/scheduler.h
+++ b/src/or/scheduler.h
@@ -44,6 +44,13 @@ MOCK_DECL(STATIC int, scheduler_compare_channels,
           (const void *c1_v, const void *c2_v));
 STATIC uint64_t scheduler_get_queue_heuristic(void);
 STATIC void scheduler_update_queue_heuristic(time_t now);
+
+#ifdef TOR_UNIT_TESTS
+extern smartlist_t *channels_pending;
+extern struct event *run_sched_ev;
+extern uint64_t queue_heuristic;
+extern time_t queue_heuristic_timestamp;
+#endif
 #endif
 
 #endif /* !defined(TOR_SCHEDULER_H) */
diff --git a/src/or/tor_main.c b/src/or/tor_main.c
index ac32eef55..21fbe3efb 100644
--- a/src/or/tor_main.c
+++ b/src/or/tor_main.c
@@ -3,6 +3,8 @@
  * Copyright (c) 2007-2016, The Tor Project, Inc. */
 /* See LICENSE for licensing information */
 
+extern const char tor_git_revision[];
+
 /** String describing which Tor Git repository version the source was
  * built from.  This string is generated by a bit of shell kludging in
  * src/or/include.am, and is usually right.
diff --git a/src/test/bench.c b/src/test/bench.c
index 5aefda5ff..5595988f3 100644
--- a/src/test/bench.c
+++ b/src/test/bench.c
@@ -3,6 +3,7 @@
  * Copyright (c) 2007-2016, The Tor Project, Inc. */
 /* See LICENSE for licensing information */
 
+extern const char tor_git_revision[];
 /* Ordinarily defined in tor_main.c; this bit is just here to provide one
  * since we're not linking to tor_main.c */
 const char tor_git_revision[] = "";
diff --git a/src/test/example_extrainfo.inc b/src/test/example_extrainfo.inc
index e096afd6c..0bf2341ef 100644
--- a/src/test/example_extrainfo.inc
+++ b/src/test/example_extrainfo.inc
@@ -133,7 +133,7 @@ static const char EX_EI_BAD_NICKNAME_KEY[] =
   "/UBWNSyXCFDMqnddb/LZ8+VgttmxfYkpeRzSSmDijN3RbOvYJhhBAgMBAAE=\n"
   "-----END RSA PUBLIC KEY-----\n";
 
-const char EX_EI_BAD_TOKENS[] =
+static const char EX_EI_BAD_TOKENS[] =
   "extra-info bob 6F314FB01A31162BD5E473D4977AC570DC5B86BB\n"
   "published 2014-10-05 20:07:00\n"
   "published 2014-10-05 20:07:00\n"
@@ -145,8 +145,9 @@ const char EX_EI_BAD_TOKENS[] =
   "-----END SIGNATURE-----\n"
   ;
 
-const char EX_EI_BAD_TOKENS_FP[] = "6F314FB01A31162BD5E473D4977AC570DC5B86BB";
-const char EX_EI_BAD_TOKENS_KEY[] =
+static const char EX_EI_BAD_TOKENS_FP[] =
+  "6F314FB01A31162BD5E473D4977AC570DC5B86BB";
+static const char EX_EI_BAD_TOKENS_KEY[] =
   "-----BEGIN RSA PUBLIC KEY-----\n"
   "MIGJAoGBAL7Z8tz45Tb4tnEFS2sAyjubBV/giSfZdmXRkDV8Jo4xqWqhWFJn7+zN\n"
   "AXBWBThGeVH2WXrpz5seNJXgZJPxMTMsrnSCGcRXZw0Npti2MkLuQ6+prZa+OPwE\n"
@@ -210,7 +211,8 @@ static const char EX_EI_GOOD_ED_EI[] =
   "\n"
   "\n"
   ;
-const char EX_EI_GOOD_ED_EI_FP[] = "A692FE045C32B5E3A54B52882EF678A9DAC46A73";
+static const char EX_EI_GOOD_ED_EI_FP[] =
+  "A692FE045C32B5E3A54B52882EF678A9DAC46A73";
 static const char EX_EI_GOOD_ED_EI_KEY[] =
   "-----BEGIN RSA PUBLIC KEY-----\n"
   "MIGJAoGBAM3jdYwjwGxDWYj/vyFkQT7RgeCNIn89Ei6D2+L/fdtFnqrMXOreFFHL\n"
@@ -237,7 +239,8 @@ static const char EX_EI_ED_MISSING_SIG[] =
   "\n"
   "\n"
   ;
-const char EX_EI_ED_MISSING_SIG_FP[] = "2A7521497B91A8437021515308A47491164EDBA1";
+static const char EX_EI_ED_MISSING_SIG_FP[] =
+  "2A7521497B91A8437021515308A47491164EDBA1";
 static const char EX_EI_ED_MISSING_SIG_KEY[] =
   "-----BEGIN RSA PUBLIC KEY-----\n"
   "MIGJAoGBAOOB8ccxbtk2dB5FuKFhGndDcO6STNjB6KiG0b9X2QwKrOZMfmXSigto\n"
@@ -260,7 +263,8 @@ static const char EX_EI_ED_MISSING_CERT[] =
   "\n"
   "\n"
   ;
-const char EX_EI_ED_MISSING_CERT_FP[] = "E88E43E86015345A323D93D825C33E4AD1028F65";
+static const char EX_EI_ED_MISSING_CERT_FP[] =
+  "E88E43E86015345A323D93D825C33E4AD1028F65";
 static const char EX_EI_ED_MISSING_CERT_KEY[] =
   "-----BEGIN RSA PUBLIC KEY-----\n"
   "MIGJAoGBALjA/geb0TR9rp/UPvLhABQpB0XUDYuZAnLkrv+i7AAV7FemTDveEGnc\n"
@@ -284,7 +288,8 @@ static const char EX_EI_ED_BAD_CERT1[] =
   "-----END SIGNATURE-----\n"
   "\n"
   ;
-const char EX_EI_ED_BAD_CERT1_FP[] = "F78D8A655607D32281D02144817A4F1D26AE520F";
+static const char EX_EI_ED_BAD_CERT1_FP[] =
+  "F78D8A655607D32281D02144817A4F1D26AE520F";
 static const char EX_EI_ED_BAD_CERT1_KEY[] =
   "-----BEGIN RSA PUBLIC KEY-----\n"
   "MIGJAoGBAMlR46JhxsCmWYtmIB/JjTV2TUYIhJLmHy+X7FfkK3ZVQvvl9/3GSXFL\n"
@@ -309,7 +314,8 @@ static const char EX_EI_ED_BAD_CERT2[] =
   "cVrtU6RVmzldSbyir8V/Z4S/Cm67gYAgjM5gfoFUqDs=\n"
   "-----END SIGNATURE-----\n"
   ;
-const char EX_EI_ED_BAD_CERT2_FP[] = "7C2B42E783C4E0EB0CC3BDB37385D16737BACFBD";
+static const char EX_EI_ED_BAD_CERT2_FP[] =
+  "7C2B42E783C4E0EB0CC3BDB37385D16737BACFBD";
 static const char EX_EI_ED_BAD_CERT2_KEY[] =
   "-----BEGIN RSA PUBLIC KEY-----\n"
   "MIGJAoGBALAM1F/0XJEsbxIQqb3+ObX/yGVnq9of8Q9sLsmxffD6hwVpCqnV3lTg\n"
@@ -335,7 +341,8 @@ static const char EX_EI_ED_BAD_SIG1[] =
   "-----END SIGNATURE-----\n"
   "\n"
   ;
-const char EX_EI_ED_BAD_SIG1_FP[] = "5AC3A538FEEFC6F9FCC5FA0CE64704396C30D62A";
+static const char EX_EI_ED_BAD_SIG1_FP[] =
+  "5AC3A538FEEFC6F9FCC5FA0CE64704396C30D62A";
 static const char EX_EI_ED_BAD_SIG1_KEY[] =
   "-----BEGIN RSA PUBLIC KEY-----\n"
   "MIGJAoGBAMvb6SuoIkPfBkJgQuo5aQDepAs1kEETZ9VXotMlhB0JJikrqBrAAz+7\n"
@@ -361,7 +368,8 @@ static const char EX_EI_ED_BAD_SIG2[] =
   "-----END SIGNATURE-----\n"
   "\n"
   ;
-const char EX_EI_ED_BAD_SIG2_FP[] = "7F1D4DD477E340C6D6B389FAC26EDC746113082F";
+static const char EX_EI_ED_BAD_SIG2_FP[] =
+  "7F1D4DD477E340C6D6B389FAC26EDC746113082F";
 static const char EX_EI_ED_BAD_SIG2_KEY[] =
   "-----BEGIN RSA PUBLIC KEY-----\n"
   "MIGJAoGBALzOyfCEUZnvCyhlyMctPkdXg/XRE3Cr6QgyzdKf5kQbUiu2n0FgSHOX\n"
@@ -388,7 +396,8 @@ static const char EX_EI_ED_MISPLACED_CERT[] =
   "-----END SIGNATURE-----\n"
   "\n"
   ;
-const char EX_EI_ED_MISPLACED_CERT_FP[] = "3B788BD0CE348BC5CED48313307C78175EB6D0F3";
+static const char EX_EI_ED_MISPLACED_CERT_FP[] =
+  "3B788BD0CE348BC5CED48313307C78175EB6D0F3";
 static const char EX_EI_ED_MISPLACED_CERT_KEY[] =
   "-----BEGIN RSA PUBLIC KEY-----\n"
   "MIGJAoGBALTwNqhTprg1oC6bEbDqwIYBoER6prqUXQFbwbFDn+ekXhZj8vltgGwp\n"
@@ -414,7 +423,8 @@ static const char EX_EI_ED_MISPLACED_SIG[] =
   "-----END SIGNATURE-----\n"
   "\n"
   ;
-const char EX_EI_ED_MISPLACED_SIG_FP[] = "384E40A5DEED4AB1D8A74F1FCBDB18B7C24A8284";
+static const char EX_EI_ED_MISPLACED_SIG_FP[] =
+  "384E40A5DEED4AB1D8A74F1FCBDB18B7C24A8284";
 static const char EX_EI_ED_MISPLACED_SIG_KEY[] =
   "-----BEGIN RSA PUBLIC KEY-----\n"
   "MIGJAoGBAK0HgOCG/6433VCrwz/vhk3cKmyOfenCp0GZ4DIUwPWt4DeyP4nTbN6T\n"
diff --git a/src/test/test-memwipe.c b/src/test/test-memwipe.c
index 5e89534db..c28d5054a 100644
--- a/src/test/test-memwipe.c
+++ b/src/test/test-memwipe.c
@@ -14,6 +14,7 @@ static unsigned fill_heap_buffer_memwipe(void) __attribute__((noinline));
 static unsigned fill_heap_buffer_nothing(void) __attribute__((noinline));
 static unsigned check_a_buffer(void) __attribute__((noinline));
 
+extern const char *s; /* Make the linkage global */
 const char *s = NULL;
 
 #define BUF_LEN 2048
diff --git a/src/test/test.c b/src/test/test.c
index 1595c8ee4..c0faec302 100644
--- a/src/test/test.c
+++ b/src/test/test.c
@@ -1124,62 +1124,6 @@ static struct testcase_t test_array[] = {
   END_OF_TESTCASES
 };
 
-extern struct testcase_t accounting_tests[];
-extern struct testcase_t addr_tests[];
-extern struct testcase_t address_tests[];
-extern struct testcase_t buffer_tests[];
-extern struct testcase_t cell_format_tests[];
-extern struct testcase_t cell_queue_tests[];
-extern struct testcase_t channel_tests[];
-extern struct testcase_t channeltls_tests[];
-extern struct testcase_t checkdir_tests[];
-extern struct testcase_t circuitlist_tests[];
-extern struct testcase_t circuitmux_tests[];
-extern struct testcase_t compat_libevent_tests[];
-extern struct testcase_t config_tests[];
-extern struct testcase_t connection_tests[];
-extern struct testcase_t container_tests[];
-extern struct testcase_t controller_tests[];
-extern struct testcase_t controller_event_tests[];
-extern struct testcase_t crypto_tests[];
-extern struct testcase_t dir_tests[];
-extern struct testcase_t dir_handle_get_tests[];
-extern struct testcase_t entryconn_tests[];
-extern struct testcase_t entrynodes_tests[];
-extern struct testcase_t guardfraction_tests[];
-extern struct testcase_t extorport_tests[];
-extern struct testcase_t hs_tests[];
-extern struct testcase_t introduce_tests[];
-extern struct testcase_t keypin_tests[];
-extern struct testcase_t link_handshake_tests[];
-extern struct testcase_t logging_tests[];
-extern struct testcase_t microdesc_tests[];
-extern struct testcase_t nodelist_tests[];
-extern struct testcase_t oom_tests[];
-extern struct testcase_t options_tests[];
-extern struct testcase_t policy_tests[];
-extern struct testcase_t procmon_tests[];
-extern struct testcase_t pubsub_tests[];
-extern struct testcase_t pt_tests[];
-extern struct testcase_t relay_tests[];
-extern struct testcase_t relaycell_tests[];
-extern struct testcase_t rend_cache_tests[];
-extern struct testcase_t replaycache_tests[];
-extern struct testcase_t router_tests[];
-extern struct testcase_t routerkeys_tests[];
-extern struct testcase_t routerlist_tests[];
-extern struct testcase_t routerset_tests[];
-extern struct testcase_t scheduler_tests[];
-extern struct testcase_t socks_tests[];
-extern struct testcase_t status_tests[];
-extern struct testcase_t thread_tests[];
-extern struct testcase_t tortls_tests[];
-extern struct testcase_t util_tests[];
-extern struct testcase_t util_format_tests[];
-extern struct testcase_t util_process_tests[];
-extern struct testcase_t dns_tests[];
-extern struct testcase_t handle_tests[];
-
 struct testgroup_t testgroups[] = {
   { "", test_array },
   { "accounting/", accounting_tests },
diff --git a/src/test/test.h b/src/test/test.h
index 153b7cae0..747b61d66 100644
--- a/src/test/test.h
+++ b/src/test/test.h
@@ -163,11 +163,86 @@ struct crypto_pk_t *pk_generate(int idx);
 
 #define CALLED(mock_name) US_CONCAT_2_(NS(mock_name), called)
 #define NS_DECL(retval, mock_fn, args) \
+    extern int CALLED(mock_fn);        \
     static retval NS(mock_fn) args; int CALLED(mock_fn) = 0
 #define NS_MOCK(name) MOCK(name, NS(name))
 #define NS_UNMOCK(name) UNMOCK(name)
 
 extern const struct testcase_setup_t passthrough_setup;
 
+extern struct testcase_t accounting_tests[];
+extern struct testcase_t addr_tests[];
+extern struct testcase_t address_tests[];
+extern struct testcase_t buffer_tests[];
+extern struct testcase_t cell_format_tests[];
+extern struct testcase_t cell_queue_tests[];
+extern struct testcase_t channel_tests[];
+extern struct testcase_t channeltls_tests[];
+extern struct testcase_t checkdir_tests[];
+extern struct testcase_t circuitlist_tests[];
+extern struct testcase_t circuitmux_tests[];
+extern struct testcase_t compat_libevent_tests[];
+extern struct testcase_t config_tests[];
+extern struct testcase_t connection_tests[];
+extern struct testcase_t container_tests[];
+extern struct testcase_t controller_tests[];
+extern struct testcase_t controller_event_tests[];
+extern struct testcase_t crypto_tests[];
+extern struct testcase_t dir_tests[];
+extern struct testcase_t dir_handle_get_tests[];
+extern struct testcase_t entryconn_tests[];
+extern struct testcase_t entrynodes_tests[];
+extern struct testcase_t guardfraction_tests[];
+extern struct testcase_t extorport_tests[];
+extern struct testcase_t hs_tests[];
+extern struct testcase_t introduce_tests[];
+extern struct testcase_t keypin_tests[];
+extern struct testcase_t link_handshake_tests[];
+extern struct testcase_t logging_tests[];
+extern struct testcase_t microdesc_tests[];
+extern struct testcase_t nodelist_tests[];
+extern struct testcase_t oom_tests[];
+extern struct testcase_t options_tests[];
+extern struct testcase_t policy_tests[];
+extern struct testcase_t procmon_tests[];
+extern struct testcase_t pubsub_tests[];
+extern struct testcase_t pt_tests[];
+extern struct testcase_t relay_tests[];
+extern struct testcase_t relaycell_tests[];
+extern struct testcase_t rend_cache_tests[];
+extern struct testcase_t replaycache_tests[];
+extern struct testcase_t router_tests[];
+extern struct testcase_t routerkeys_tests[];
+extern struct testcase_t routerlist_tests[];
+extern struct testcase_t routerset_tests[];
+extern struct testcase_t scheduler_tests[];
+extern struct testcase_t socks_tests[];
+extern struct testcase_t status_tests[];
+extern struct testcase_t thread_tests[];
+extern struct testcase_t tortls_tests[];
+extern struct testcase_t util_tests[];
+extern struct testcase_t util_format_tests[];
+extern struct testcase_t util_process_tests[];
+extern struct testcase_t dns_tests[];
+extern struct testcase_t handle_tests[];
+
+extern struct testcase_t slow_crypto_tests[];
+extern struct testcase_t slow_util_tests[];
+
+extern struct testgroup_t testgroups[];
+
+extern const char AUTHORITY_CERT_1[];
+extern const char AUTHORITY_SIGNKEY_1[];
+extern const char AUTHORITY_SIGNKEY_A_DIGEST[];
+extern const char AUTHORITY_SIGNKEY_A_DIGEST256[];
+extern const char AUTHORITY_CERT_2[];
+extern const char AUTHORITY_SIGNKEY_2[];
+extern const char AUTHORITY_SIGNKEY_B_DIGEST[];
+extern const char AUTHORITY_SIGNKEY_B_DIGEST256[];
+extern const char AUTHORITY_CERT_3[];
+extern const char AUTHORITY_SIGNKEY_3[];
+extern const char AUTHORITY_SIGNKEY_C_DIGEST[];
+extern const char AUTHORITY_SIGNKEY_C_DIGEST256[];
+
 #endif
 
diff --git a/src/test/test_buffers.c b/src/test/test_buffers.c
index e5e56edf7..95584d54a 100644
--- a/src/test/test_buffers.c
+++ b/src/test/test_buffers.c
@@ -695,9 +695,9 @@ test_buffers_zlib_fin_at_chunk_end(void *arg)
   tor_free(msg);
 }
 
-const uint8_t *tls_read_ptr;
-int n_remaining;
-int next_reply_val[16];
+static const uint8_t *tls_read_ptr;
+static int n_remaining;
+static int next_reply_val[16];
 
 static int
 mock_tls_read(tor_tls_t *tls, char *cp, size_t len)
diff --git a/src/test/test_channel.c b/src/test/test_channel.c
index f37e71816..a9e0634d9 100644
--- a/src/test/test_channel.c
+++ b/src/test/test_channel.c
@@ -20,9 +20,6 @@
 #include "test.h"
 #include "fakechans.h"
 
-/* This comes from channel.c */
-extern uint64_t estimated_total_queue_size;
-
 static int test_chan_accept_cells = 0;
 static int test_chan_fixed_cells_recved = 0;
 static cell_t * test_chan_last_seen_fixed_cell_ptr = NULL;
diff --git a/src/test/test_crypto.c b/src/test/test_crypto.c
index e6b250a67..636233194 100644
--- a/src/test/test_crypto.c
+++ b/src/test/test_crypto.c
@@ -18,10 +18,6 @@
 #include <openssl/evp.h>
 #include <openssl/rand.h>
 
-extern const char AUTHORITY_SIGNKEY_3[];
-extern const char AUTHORITY_SIGNKEY_A_DIGEST[];
-extern const char AUTHORITY_SIGNKEY_A_DIGEST256[];
-
 /** Run unit tests for Diffie-Hellman functionality. */
 static void
 test_crypto_dh(void *arg)
@@ -275,9 +271,6 @@ test_crypto_rng_range(void *arg)
   ;
 }
 
-extern int break_strongest_rng_fallback;
-extern int break_strongest_rng_syscall;
-
 static void
 test_crypto_rng_strongest(void *arg)
 {
diff --git a/src/test/test_data.c b/src/test/test_data.c
index 32de54bc8..788489a09 100644
--- a/src/test/test_data.c
+++ b/src/test/test_data.c
@@ -3,6 +3,8 @@
  * Copyright (c) 2007-2016, The Tor Project, Inc. */
 /* See LICENSE for licensing information */
 
+#include "test.h"
+
 /* Our unit test expect that the AUTHORITY_CERT_* public keys will sort
  * in this order. */
 #define AUTHORITY_CERT_A AUTHORITY_CERT_3
diff --git a/src/test/test_dir_common.c b/src/test/test_dir_common.c
index 0b446c2df..2448d307b 100644
--- a/src/test/test_dir_common.c
+++ b/src/test/test_dir_common.c
@@ -21,13 +21,6 @@ networkstatus_t * dir_common_add_rs_and_parse(networkstatus_t *vote,
                             crypto_pk_t *sign_skey, int *n_vrs,
                             time_t now, int clear_rl);
 
-extern const char AUTHORITY_CERT_1[];
-extern const char AUTHORITY_SIGNKEY_1[];
-extern const char AUTHORITY_CERT_2[];
-extern const char AUTHORITY_SIGNKEY_2[];
-extern const char AUTHORITY_CERT_3[];
-extern const char AUTHORITY_SIGNKEY_3[];
-
 /** Initialize and set auth certs and keys
  * Returns 0 on success, -1 on failure. Clean up handled by caller.
  */
diff --git a/src/test/test_dir_handle_get.c b/src/test/test_dir_handle_get.c
index 44edaf850..9e47deb74 100644
--- a/src/test/test_dir_handle_get.c
+++ b/src/test/test_dir_handle_get.c
@@ -1212,8 +1212,6 @@ test_dir_handle_get_server_keys_all_not_found(void* data)
 
 #define TEST_CERTIFICATE AUTHORITY_CERT_3
 #define TEST_SIGNING_KEY AUTHORITY_SIGNKEY_A_DIGEST
-extern const char AUTHORITY_CERT_3[];
-extern const char AUTHORITY_SIGNKEY_A_DIGEST[];
 
 static const char TEST_CERT_IDENT_KEY[] =
   "D867ACF56A9D229B35C25F0090BC9867E906BE69";
diff --git a/src/test/test_introduce.c b/src/test/test_introduce.c
index 9c7a86da6..810b03c93 100644
--- a/src/test/test_introduce.c
+++ b/src/test/test_introduce.c
@@ -9,8 +9,6 @@
 #define RENDSERVICE_PRIVATE
 #include "rendservice.h"
 
-extern const char AUTHORITY_SIGNKEY_1[];
-
 static uint8_t v0_test_plaintext[] =
     /* 20 bytes of rendezvous point nickname */
   { 0x4e, 0x69, 0x63, 0x6b, 0x6e, 0x61, 0x6d, 0x65,
diff --git a/src/test/test_link_handshake.c b/src/test/test_link_handshake.c
index e8856c60d..403878345 100644
--- a/src/test/test_link_handshake.c
+++ b/src/test/test_link_handshake.c
@@ -16,7 +16,7 @@
 
 #include "test.h"
 
-var_cell_t *mock_got_var_cell = NULL;
+static var_cell_t *mock_got_var_cell = NULL;
 
 static void
 mock_write_var_cell(const var_cell_t *vc, or_connection_t *conn)
diff --git a/src/test/test_options.c b/src/test/test_options.c
index 20e8dd563..8d1d6f901 100644
--- a/src/test/test_options.c
+++ b/src/test/test_options.c
@@ -12,7 +12,7 @@
 
 #define ROUTERSET_PRIVATE
 #include "routerset.h"
-
+#include "main.h"
 #include "log_test_helpers.h"
 
 #include "sandbox.h"
@@ -572,8 +572,6 @@ test_options_validate__contactinfo(void *ignored)
   tor_free(msg);
 }
 
-extern int quiet_level;
-
 static void
 test_options_validate__logs(void *ignored)
 {
diff --git a/src/test/test_policy.c b/src/test/test_policy.c
index a939ebf54..913a2f303 100644
--- a/src/test/test_policy.c
+++ b/src/test/test_policy.c
@@ -778,8 +778,8 @@ test_policies_reject_port_address(void *arg)
   UNMOCK(get_configured_ports);
 }
 
-smartlist_t *mock_ipv4_addrs = NULL;
-smartlist_t *mock_ipv6_addrs = NULL;
+static smartlist_t *mock_ipv4_addrs = NULL;
+static smartlist_t *mock_ipv6_addrs = NULL;
 
 /* mock get_interface_address6_list, returning a deep copy of the template
  * address list ipv4_interface_address_list or ipv6_interface_address_list */
diff --git a/src/test/test_rendcache.c b/src/test/test_rendcache.c
index d1b52649b..eac41ecdd 100644
--- a/src/test/test_rendcache.c
+++ b/src/test/test_rendcache.c
@@ -20,11 +20,6 @@ static const int TIME_IN_THE_PAST = -(REND_CACHE_MAX_AGE + \
                                       REND_CACHE_MAX_SKEW + 10);
 static const int TIME_IN_THE_FUTURE = REND_CACHE_MAX_SKEW + 10;
 
-extern strmap_t *rend_cache;
-extern digestmap_t *rend_cache_v2_dir;
-extern strmap_t *rend_cache_failure;
-extern size_t rend_cache_total_allocation;
-
 static rend_data_t *
 mock_rend_data(const char *onion_address)
 {
diff --git a/src/test/test_routerlist.c b/src/test/test_routerlist.c
index 2cffa6e80..34b70ac8a 100644
--- a/src/test/test_routerlist.c
+++ b/src/test/test_routerlist.c
@@ -24,13 +24,6 @@
 #include "test.h"
 #include "test_dir_common.h"
 
-extern const char AUTHORITY_CERT_1[];
-extern const char AUTHORITY_SIGNKEY_1[];
-extern const char AUTHORITY_CERT_2[];
-extern const char AUTHORITY_SIGNKEY_2[];
-extern const char AUTHORITY_CERT_3[];
-extern const char AUTHORITY_SIGNKEY_3[];
-
 void construct_consensus(char **consensus_text_md);
 
 /* 4 digests + 3 sep + pre + post + NULL */
@@ -423,7 +416,7 @@ test_router_pick_directory_server_impl(void *arg)
   networkstatus_vote_free(con_md);
 }
 
-connection_t *mocked_connection = NULL;
+static connection_t *mocked_connection = NULL;
 
 /* Mock connection_get_by_type_addr_port_purpose by returning
  * mocked_connection. */
diff --git a/src/test/test_routerset.c b/src/test/test_routerset.c
index 74b39c048..1b526d430 100644
--- a/src/test/test_routerset.c
+++ b/src/test/test_routerset.c
@@ -432,7 +432,7 @@ NS(test_main)(void *arg)
 NS_DECL(addr_policy_t *, router_parse_addr_policy_item_from_string,
     (const char *s, int assume_action, int *malformed_list));
 
-addr_policy_t *NS(mock_addr_policy);
+static addr_policy_t *NS(mock_addr_policy);
 
 static void
 NS(test_main)(void *arg)
@@ -480,7 +480,7 @@ NS(router_parse_addr_policy_item_from_string)(const char *s,
 NS_DECL(addr_policy_t *, router_parse_addr_policy_item_from_string,
         (const char *s, int assume_action, int *bogus));
 
-addr_policy_t *NS(mock_addr_policy);
+static addr_policy_t *NS(mock_addr_policy);
 
 static void
 NS(test_main)(void *arg)
@@ -527,7 +527,7 @@ NS(router_parse_addr_policy_item_from_string)(const char *s, int assume_action,
 NS_DECL(addr_policy_t *, router_parse_addr_policy_item_from_string,
         (const char *s, int assume_action, int *bad));
 
-addr_policy_t *NS(mock_addr_policy);
+static addr_policy_t *NS(mock_addr_policy);
 
 static void
 NS(test_main)(void *arg)
@@ -1477,7 +1477,7 @@ NS(test_main)(void *arg)
  * routerset or routerinfo.
  */
 
-node_t NS(mock_node);
+static node_t NS(mock_node);
 
 static void
 NS(test_main)(void *arg)
@@ -1504,7 +1504,7 @@ NS(test_main)(void *arg)
  * routerset and no routerinfo.
  */
 
-node_t NS(mock_node);
+static node_t NS(mock_node);
 
 static void
 NS(test_main)(void *arg)
@@ -1603,7 +1603,7 @@ NS(test_main)(void *arg)
 
 NS_DECL(const node_t *, node_get_by_nickname,
     (const char *nickname, int warn_if_unused));
-const char *NS(mock_nickname);
+static const char *NS(mock_nickname);
 
 static void
 NS(test_main)(void *arg)
@@ -1652,8 +1652,8 @@ NS(node_get_by_nickname)(const char *nickname, int warn_if_unused)
 
 NS_DECL(const node_t *, node_get_by_nickname,
     (const char *nickname, int warn_if_unused));
-const char *NS(mock_nickname);
-node_t NS(mock_node);
+static const char *NS(mock_nickname);
+static node_t NS(mock_node);
 
 static void
 NS(test_main)(void *arg)
@@ -1702,8 +1702,8 @@ NS(node_get_by_nickname)(const char *nickname, int warn_if_unused)
 
 NS_DECL(const node_t *, node_get_by_nickname,
     (const char *nickname, int warn_if_unused));
-char *NS(mock_nickname);
-node_t NS(mock_node);
+static char *NS(mock_nickname);
+static node_t NS(mock_node);
 
 static void
 NS(test_main)(void *arg)
@@ -1754,7 +1754,7 @@ NS(node_get_by_nickname)(const char *nickname, int warn_if_unused)
 
 NS_DECL(smartlist_t *, nodelist_get_list, (void));
 
-smartlist_t *NS(mock_smartlist);
+static smartlist_t *NS(mock_smartlist);
 
 static void
 NS(test_main)(void *arg)
@@ -1800,8 +1800,8 @@ NS(nodelist_get_list)(void)
 
 NS_DECL(smartlist_t *, nodelist_get_list, (void));
 
-smartlist_t *NS(mock_smartlist);
-node_t NS(mock_node);
+static smartlist_t *NS(mock_smartlist);
+static node_t NS(mock_node);
 
 static void
 NS(test_main)(void *arg)
diff --git a/src/test/test_scheduler.c b/src/test/test_scheduler.c
index 6e9889b48..15fbb2d18 100644
--- a/src/test/test_scheduler.c
+++ b/src/test/test_scheduler.c
@@ -24,12 +24,6 @@
 #include "test.h"
 #include "fakechans.h"
 
-/* Statics in scheduler.c exposed to the test suite */
-extern smartlist_t *channels_pending;
-extern struct event *run_sched_ev;
-extern uint64_t queue_heuristic;
-extern time_t queue_heuristic_timestamp;
-
 /* Event base for scheduelr tests */
 static struct event_base *mock_event_base = NULL;
 
diff --git a/src/test/test_slow.c b/src/test/test_slow.c
index c1d2e8191..7c9f0b1cc 100644
--- a/src/test/test_slow.c
+++ b/src/test/test_slow.c
@@ -18,9 +18,6 @@
 #include "or.h"
 #include "test.h"
 
-extern struct testcase_t slow_crypto_tests[];
-extern struct testcase_t slow_util_tests[];
-
 struct testgroup_t testgroups[] = {
   { "slow/crypto/", slow_crypto_tests },
   { "slow/util/", slow_util_tests },
diff --git a/src/test/test_socks.c b/src/test/test_socks.c
index 6da09fd65..62ff12fe1 100644
--- a/src/test/test_socks.c
+++ b/src/test/test_socks.c
@@ -34,7 +34,7 @@ socks_test_cleanup(const struct testcase_t *testcase, void *ptr)
   return 1;
 }
 
-const struct testcase_setup_t socks_setup = {
+static const struct testcase_setup_t socks_setup = {
   socks_test_setup, socks_test_cleanup
 };
 
diff --git a/src/test/test_status.c b/src/test/test_status.c
index 84a0f6c02..b4438aabe 100644
--- a/src/test/test_status.c
+++ b/src/test/test_status.c
@@ -310,8 +310,6 @@ NS_DECL(void, logv, (int severity, log_domain_mask_t domain,
 NS_DECL(int, server_mode, (const or_options_t *options));
 
 static routerinfo_t *mock_routerinfo;
-extern int onion_handshakes_requested[MAX_ONION_HANDSHAKE_TYPE+1];
-extern int onion_handshakes_assigned[MAX_ONION_HANDSHAKE_TYPE+1];
 
 static void
 NS(test_main)(void *arg)
diff --git a/src/test/test_tortls.c b/src/test/test_tortls.c
index caaada870..42b9ef773 100644
--- a/src/test/test_tortls.c
+++ b/src/test/test_tortls.c
@@ -51,9 +51,6 @@
 #include "log_test_helpers.h"
 #define NS_MODULE tortls
 
-extern tor_tls_context_t *server_tls_context;
-extern tor_tls_context_t *client_tls_context;
-
 #if OPENSSL_VERSION_NUMBER >= OPENSSL_V_SERIES(1,1,0) \
     && !defined(LIBRESSL_VERSION_NUMBER)
 #define OPENSSL_OPAQUE
@@ -278,8 +275,6 @@ test_tortls_get_state_description(void *ignored)
   tor_free(tls);
 }
 
-extern int tor_tls_object_ex_data_index;
-
 static void
 test_tortls_get_by_ssl(void *ignored)
 {
@@ -790,8 +785,6 @@ get_cipher_by_id(uint16_t id)
   return NULL;
 }
 
-extern uint16_t v2_cipher_list[];
-
 static void
 test_tortls_classify_client_ciphers(void *ignored)
 {
@@ -1184,9 +1177,6 @@ test_tortls_get_forced_write_size(void *ignored)
   tor_free(tls);
 }
 
-extern uint64_t total_bytes_written_over_tls;
-extern uint64_t total_bytes_written_by_tls;
-
 static void
 test_tortls_get_write_overhead_ratio(void *ignored)
 {
diff --git a/src/test/testing_common.c b/src/test/testing_common.c
index 39c3d02ab..ea9366305 100644
--- a/src/test/testing_common.c
+++ b/src/test/testing_common.c
@@ -3,6 +3,8 @@
  * Copyright (c) 2007-2016, The Tor Project, Inc. */
 /* See LICENSE for licensing information */
 
+extern const char tor_git_revision[];
+
 /* Ordinarily defined in tor_main.c; this bit is just here to provide one
  * since we're not linking to tor_main.c */
 const char tor_git_revision[] = "";
@@ -215,8 +217,6 @@ const struct testcase_setup_t passthrough_setup = {
   passthrough_test_setup, passthrough_test_cleanup
 };
 
-extern struct testgroup_t testgroups[];
-
 /** Main entry point for unit test code: parse the command line, and run
  * some unit tests. */
 int
diff --git a/src/test/vote_descriptors.inc b/src/test/vote_descriptors.inc
index c5ce21f74..895dc6c65 100644
--- a/src/test/vote_descriptors.inc
+++ b/src/test/vote_descriptors.inc
@@ -1,4 +1,4 @@
-const char* VOTE_BODY_V3 = 
+static const char* VOTE_BODY_V3 =
 "network-status-version 3\n"
 "vote-status vote\n"
 "consensus-methods 13 14 15 16 17 18 19 20 21\n"
diff --git a/src/tools/tor-gencert.c b/src/tools/tor-gencert.c
index c05066722..778196602 100644
--- a/src/tools/tor-gencert.c
+++ b/src/tools/tor-gencert.c
@@ -39,21 +39,21 @@
 #define DEFAULT_LIFETIME 12
 
 /* These globals are set via command line options. */
-char *identity_key_file = NULL;
-char *signing_key_file = NULL;
-char *certificate_file = NULL;
-int reuse_signing_key = 0;
-int verbose = 0;
-int make_new_id = 0;
-int months_lifetime = DEFAULT_LIFETIME;
-int passphrase_fd = -1;
-char *address = NULL;
+static char *identity_key_file = NULL;
+static char *signing_key_file = NULL;
+static char *certificate_file = NULL;
+static int reuse_signing_key = 0;
+static int verbose = 0;
+static int make_new_id = 0;
+static int months_lifetime = DEFAULT_LIFETIME;
+static int passphrase_fd = -1;
+static char *address = NULL;
 
-char *passphrase = NULL;
-size_t passphrase_len = 0;
+static char *passphrase = NULL;
+static size_t passphrase_len = 0;
 
-EVP_PKEY *identity_key = NULL;
-EVP_PKEY *signing_key = NULL;
+static EVP_PKEY *identity_key = NULL;
+static EVP_PKEY *signing_key = NULL;
 
 /** Write a usage message for tor-gencert to stderr. */
 static void