diff --git a/configure.in b/configure.in
index fb6a02859..6c82d10c8 100644
--- a/configure.in
+++ b/configure.in
@@ -335,6 +335,17 @@ AC_CHECK_SIZEOF(long long)
 AC_CHECK_SIZEOF(__int64)
 AC_CHECK_SIZEOF(void *)
 AC_CHECK_SIZEOF(time_t)
+AC_CACHE_CHECK([whether time_t is signed], tor_cv_time_t_signed, [
+AC_TRY_RUN([
+int main(int c, char**v) { if (((time_t)-1)<0) return 1; else return 0; }],
+  tor_cv_time_t_signed=no, tor_cv_time_t_signed=yes)
+])
+
+if test $tor_cv_time_t_signed = yes; then
+  AC_DEFINE([TIME_T_IS_SIGNED], 1,
+            [Define to 1 iff time_t is signed])
+fi
+
 AC_CHECK_SIZEOF(socklen_t, , [AC_INCLUDES_DEFAULT()
 #ifdef HAVE_SYS_SOCKET_H
 #include <sys/socket.h>
diff --git a/src/common/torint.h b/src/common/torint.h
index 96464a29a..baaca80b7 100644
--- a/src/common/torint.h
+++ b/src/common/torint.h
@@ -224,6 +224,16 @@ typedef uint32_t uintptr_t;
 #endif
 #endif
 
+#ifndef INT_MAX
+#if (SIZEOF_INT == 4)
+#define INT_MAX 0x7fffffffL
+#elif (SIZEOF_INT == 8)
+#define INT_MAX 0x7fffffffffffffffL
+#else
+#error "Can't define INT_MAX"
+#endif
+#endif
+
 #ifndef UINT_MAX
 #if (SIZEOF_INT == 2)
 #define UINT_MAX 0xffffu
@@ -237,14 +247,28 @@ typedef uint32_t uintptr_t;
 #endif
 
 #ifndef TIME_MAX
+
+#ifdef TIME_T_IS_SIGNED
+
+#if (SIZEOF_TIME_T == SIZEOF_INT)
+#define TIME_MAX ((time_t)INT_MAX)
+#elif (SIZEOF_TIME_T == SIZEOF_LONG)
+#define TIME_MAX ((time_t)LONG_MAX)
+#else
+#error "Can't define (signed) TIME_MAX"
+#endif
+
+#else
+/* Unsigned case */
 #if (SIZEOF_TIME_T == 4)
 #define TIME_MAX ((time_t)UINT32_MAX)
 #elif (SIZEOF_TIME_T == 8)
 #define TIME_MAX ((time_t)UINT64_MAX)
 #else
-#error "Can't define TIME_MAX"
-#endif
+#error "Can't define (unsigned) TIME_MAX"
 #endif
+#endif /* time_t_is_signed */
+#endif /* ifndef(TIME_MAX) */
 
 /* Any size_t larger than this amount is likely to be an underflow. */
 #define SIZE_T_CEILING (sizeof(char)<<(sizeof(size_t)*8 - 1))