diff --git a/SocketRocket/Internal/Utilities/SRHTTPConnectMessage.m b/SocketRocket/Internal/Utilities/SRHTTPConnectMessage.m
index a111a6d62..a22f3a078 100644
--- a/SocketRocket/Internal/Utilities/SRHTTPConnectMessage.m
+++ b/SocketRocket/Internal/Utilities/SRHTTPConnectMessage.m
@@ -17,7 +17,11 @@
 {
     NSString *host = url.host;
     if (url.port) {
-        host = [host stringByAppendingFormat:@":%@", url.port];
+        if ([host containsString:@":"]) {
+            host = [NSString stringWithFormat:@"[%@]:%@", host, url.port];
+        } else {
+            host = [host stringByAppendingFormat:@":%@", url.port];
+        }
     }
     return host;
 }
diff --git a/SocketRocket/Internal/Utilities/SRURLUtilities.m b/SocketRocket/Internal/Utilities/SRURLUtilities.m
index fbb942961..1d7e45378 100644
--- a/SocketRocket/Internal/Utilities/SRURLUtilities.m
+++ b/SocketRocket/Internal/Utilities/SRURLUtilities.m
@@ -23,7 +23,13 @@
     } else if ([scheme isEqualToString:@"ws"]) {
         scheme = @"http";
     }
-    [origin appendFormat:@"%@://%@", scheme, url.host];
+
+    NSString * host = url.host;
+    if ([host containsString:@":"]) {
+        host = [NSString stringWithFormat:@"[%@]", host];
+    }
+
+    [origin appendFormat:@"%@://%@", scheme, host];
 
     NSNumber *port = url.port;
     BOOL portIsDefault = (!port ||