diff --git a/src/pkg/net/http/proxy_test.go b/src/pkg/net/http/proxy_test.go
index 9b320b3aa5..5ecffaface 100644
--- a/src/pkg/net/http/proxy_test.go
+++ b/src/pkg/net/http/proxy_test.go
@@ -5,6 +5,7 @@
 package http
 
 import (
+	"net/url"
 	"os"
 	"testing"
 )
@@ -46,3 +47,32 @@ func TestUseProxy(t *testing.T) {
 		}
 	}
 }
+
+var cacheKeysTests = []struct {
+	proxy  string
+	scheme string
+	addr   string
+	key    string
+}{
+	{"", "http", "foo.com", "|http|foo.com"},
+	{"", "https", "foo.com", "|https|foo.com"},
+	{"http://foo.com", "http", "foo.com", "http://foo.com|http|"},
+	{"http://foo.com", "https", "foo.com", "http://foo.com|https|foo.com"},
+}
+
+func TestCacheKeys(t *testing.T) {
+	for _, tt := range cacheKeysTests {
+		var proxy *url.URL
+		if tt.proxy != "" {
+			u, err := url.Parse(tt.proxy)
+			if err != nil {
+				t.Fatal(err)
+			}
+			proxy = u
+		}
+		cm := connectMethod{proxy, tt.scheme, tt.addr}
+		if cm.String() != tt.key {
+			t.Fatalf("{%q, %q, %q} cache key %q; want %q", tt.proxy, tt.scheme, tt.addr, cm.String(), tt.key)
+		}
+	}
+}
diff --git a/src/pkg/net/http/transport.go b/src/pkg/net/http/transport.go
index 483af556e4..dd514386ac 100644
--- a/src/pkg/net/http/transport.go
+++ b/src/pkg/net/http/transport.go
@@ -450,10 +450,14 @@ type connectMethod struct {
 
 func (ck *connectMethod) String() string {
 	proxyStr := ""
+	targetAddr := ck.targetAddr
 	if ck.proxyURL != nil {
 		proxyStr = ck.proxyURL.String()
+		if ck.targetScheme == "http" {
+			targetAddr = ""
+		}
 	}
-	return strings.Join([]string{proxyStr, ck.targetScheme, ck.targetAddr}, "|")
+	return strings.Join([]string{proxyStr, ck.targetScheme, targetAddr}, "|")
 }
 
 // addr returns the first hop "host:port" to which we need to TCP connect.