diff --git a/security/manager/ssl/tests/unit/head_psm.js b/security/manager/ssl/tests/unit/head_psm.js
index 1fee155c527..ca8bbded1c5 100644
--- a/security/manager/ssl/tests/unit/head_psm.js
+++ b/security/manager/ssl/tests/unit/head_psm.js
@@ -256,6 +256,9 @@ function add_connection_test(aHost, aExpectedResult,
     let sts = Cc["@mozilla.org/network/socket-transport-service;1"]
                 .getService(Ci.nsISocketTransportService);
     this.transport = sts.createTransport(["ssl"], 1, aHost, REMOTE_PORT, null);
+    // See bug 1129771 - attempting to connect to [::1] when the server is
+    // listening on 127.0.0.1 causes frequent failures on OS X 10.10.
+    this.transport.connectionFlags |= Ci.nsISocketTransport.DISABLE_IPV6;
     this.transport.setEventSink(this, this.thread);
     this.inputStream = null;
     this.outputStream = null;