--- a/testing/web-platform/meta/webrtc/RTCPeerConnection-generateCertificate.html.ini
+++ b/testing/web-platform/meta/webrtc/RTCPeerConnection-generateCertificate.html.ini
@@ -1,8 +1,10 @@
 [RTCPeerConnection-generateCertificate.html]
   type: testharness
   [generateCertificate() with invalid string algorithm should reject with NotSupportedError]
     expected: FAIL
 
   [generateCertificate() with invalid algorithm dict should reject with NotSupportedError]
     expected: FAIL
 
+  [generateCertificate() with 0 expires parameter should generate expired cert]
+    disabled: https://bugzilla.mozilla.org/show_bug.cgi?id=1383137