diff --git a/tests/tor_dialer_test.go b/tests/tor_dialer_test.go
index ae3ff6a..4f5003e 100644
--- a/tests/tor_dialer_test.go
+++ b/tests/tor_dialer_test.go
@@ -8,12 +8,13 @@ import (
 	"testing"
 	"time"
 
+	"github.com/cretz/bine/tor"
 	"golang.org/x/net/context/ctxhttp"
 )
 
 func TestDialerSimpleHTTP(t *testing.T) {
 	ctx := GlobalEnabledNetworkContext(t)
-	httpClient := httpClient(ctx)
+	httpClient := httpClient(ctx, nil)
 	// IsTor check
 	byts := httpGet(ctx, httpClient, "https://check.torproject.org/api/ip")
 	jsn := map[string]interface{}{}
@@ -21,12 +22,12 @@ func TestDialerSimpleHTTP(t *testing.T) {
 	ctx.Require.True(jsn["IsTor"].(bool))
 }
 
-func httpClient(ctx *TestContext) *http.Client {
+func httpClient(ctx *TestContext, conf *tor.DialConf) *http.Client {
 	// 15 seconds max to dial
 	dialCtx, dialCancel := context.WithTimeout(ctx, 15*time.Second)
 	defer dialCancel()
 	// Make connection
-	dialer, err := ctx.Dialer(dialCtx, nil)
+	dialer, err := ctx.Dialer(dialCtx, conf)
 	ctx.Require.NoError(err)
 	return &http.Client{Transport: &http.Transport{DialContext: dialer.DialContext}}
 }
diff --git a/tests/tor_isolate_socks_auth_test.go b/tests/tor_isolate_socks_auth_test.go
new file mode 100644
index 0000000..a080206
--- /dev/null
+++ b/tests/tor_isolate_socks_auth_test.go
@@ -0,0 +1,72 @@
+package tests
+
+import (
+	"context"
+	"strconv"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/cretz/bine/tor"
+	"golang.org/x/net/proxy"
+)
+
+// TestIsolateSocksAuth simply confirms the functionality of IsolateSOCKSAuth,
+// namely that it uses a different circuit for different SOCKS credentials.
+func TestIsolateSocksAuth(t *testing.T) {
+	// Create context w/ no isolate
+	ctx := NewTestContext(t, &tor.StartConf{
+		NoAutoSocksPort: true,
+		ExtraArgs:       []string{"--SocksPort", "auto NoIsolateSOCKSAuth"},
+	})
+	// Make sure it reused the circuit (i.e. only has one) for both separate-auth calls
+	uniqueCircuitIDs := doSeparateAuthHttpCalls(ctx)
+	ctx.Debugf("Unique IDs without isolate: %v", uniqueCircuitIDs)
+	ctx.Require.Len(uniqueCircuitIDs, 1)
+	// Create context w/ isolate
+	ctx = NewTestContext(t, nil)
+	// Make sure it made a new circuit (i.e. has two) for each separate-auth call
+	uniqueCircuitIDs = doSeparateAuthHttpCalls(ctx)
+	ctx.Debugf("Unique IDs with isolate: %v", uniqueCircuitIDs)
+	ctx.Require.Len(uniqueCircuitIDs, 2)
+}
+
+// Returns the map keyed with unique circuit IDs after second separate-auth HTTP call
+func doSeparateAuthHttpCalls(ctx *TestContext) map[int]struct{} {
+	defer ctx.Close()
+	enableCtx, enableCancel := context.WithTimeout(ctx, 100*time.Second)
+	defer enableCancel()
+	ctx.Require.NoError(ctx.EnableNetwork(enableCtx, true))
+	// Make HTTP call w/ an auth
+	client := httpClient(ctx, &tor.DialConf{ProxyAuth: &proxy.Auth{"foo", "bar"}})
+	byts := httpGet(ctx, client, "https://check.torproject.org/api/ip")
+	ctx.Debugf("Read bytes: %v", string(byts))
+	// Confirm just size 1
+	ids := uniqueStreamCircuitIDs(ctx)
+	ctx.Require.Len(ids, 1)
+	// Now make call with another auth and just return circuit IDs
+	client = httpClient(ctx, &tor.DialConf{ProxyAuth: &proxy.Auth{"baz", "qux"}})
+	byts = httpGet(ctx, client, "https://check.torproject.org/api/ip")
+	ctx.Debugf("Read bytes: %v", string(byts))
+	return uniqueStreamCircuitIDs(ctx)
+}
+
+// Return each stream circuit as a key of an empty-val map
+func uniqueStreamCircuitIDs(ctx *TestContext) map[int]struct{} {
+	ret := map[int]struct{}{}
+	vals, err := ctx.Control.GetInfo("stream-status")
+	ctx.Require.NoError(err)
+	for _, val := range vals {
+		ctx.Require.Equal("stream-status", val.Key)
+		for _, line := range strings.Split(val.Val, "\n") {
+			pieces := strings.Split(strings.TrimSpace(line), " ")
+			if len(pieces) < 3 {
+				continue
+			}
+			i, err := strconv.Atoi(pieces[2])
+			ctx.Require.NoError(err)
+			ret[i] = struct{}{}
+		}
+	}
+	return ret
+}
diff --git a/tests/tor_listen_test.go b/tests/tor_listen_test.go
index eade197..0feed99 100644
--- a/tests/tor_listen_test.go
+++ b/tests/tor_listen_test.go
@@ -50,7 +50,7 @@ func startHTTPServer(
 	handlePattern string,
 	handler func(http.ResponseWriter, *http.Request),
 ) (*http.Client, *http.Server, *tor.OnionService) {
-	httpClient := httpClient(ctx)
+	httpClient := httpClient(ctx, nil)
 	// Wait at most a few minutes for the entire test
 	listenCtx, listenCancel := context.WithTimeout(context.Background(), 4*time.Minute)
 	defer listenCancel()
diff --git a/tor/dialer.go b/tor/dialer.go
index 038bc95..9ef211e 100644
--- a/tor/dialer.go
+++ b/tor/dialer.go
@@ -25,8 +25,13 @@ type DialConf struct {
 	// is empty and ProxyAddress is not empty, it defaults to "tcp".
 	ProxyNetwork string
 
-	// ProxyAuth is the auth for the proxy. An empty auth means no auth, a nil
-	// auth means it is looked up.
+	// ProxyAuth is the auth for the proxy. Since Tor's SOCKS5 proxy is
+	// unauthenticated, this is rarely needed. It can be used when
+	// IsolateSOCKSAuth is set to ensure separate circuits.
+	//
+	// This should not be confused with downstream SOCKS proxy authentication
+	// which is set via Tor values for Socks5ProxyUsername and
+	// Socks5ProxyPassword when Socks5Proxy is set.
 	ProxyAuth *proxy.Auth
 
 	// SkipEnableNetwork, if true, will skip the enable network step in Dialer.
@@ -72,23 +77,8 @@ func (t *Tor) Dialer(ctx context.Context, conf *DialConf) (*Dialer, error) {
 	} else if proxyNetwork == "" {
 		proxyNetwork = "tcp"
 	}
-	// Lookup proxy auth as needed
-	proxyAuth := conf.ProxyAuth
-	if proxyAuth == nil {
-		info, err := t.Control.GetConf("Socks5ProxyUsername", "Socks5ProxyPassword")
-		if err != nil {
-			return nil, err
-		}
-		if len(info) != 2 || info[0].Key != "Socks5ProxyUsername" || info[1].Key != "Socks5ProxyPassword" {
-			return nil, fmt.Errorf("Unable to get proxy auth")
-		}
-		proxyAuth = &proxy.Auth{User: info[0].Val, Password: info[1].Val}
-	}
-	if proxyAuth.User == "" && proxyAuth.Password == "" {
-		proxyAuth = nil
-	}
 
-	dialer, err := proxy.SOCKS5(proxyNetwork, proxyAddress, proxyAuth, conf.Forward)
+	dialer, err := proxy.SOCKS5(proxyNetwork, proxyAddress, conf.ProxyAuth, conf.Forward)
 	if err != nil {
 		return nil, err
 	}