diff --git a/mozilla/content/html/document/src/nsHTMLDocument.cpp b/mozilla/content/html/document/src/nsHTMLDocument.cpp
index 962b5d57210..0ac636c45f9 100644
--- a/mozilla/content/html/document/src/nsHTMLDocument.cpp
+++ b/mozilla/content/html/document/src/nsHTMLDocument.cpp
@@ -1804,10 +1804,14 @@ nsHTMLDocument::GetDomain(nsAString& aDomain)
   }
 
   nsCAutoString hostName;
-  if (NS_FAILED(uri->GetHost(hostName)))
-    return NS_ERROR_FAILURE;
 
-  CopyUTF8toUTF16(hostName, aDomain);
+  if (NS_SUCCEEDED(uri->GetHost(hostName))) {
+    CopyUTF8toUTF16(hostName, aDomain);
+  } else {
+    // If we can't get the host from the URI (e.g. about:, javascript:,
+    // etc), just return an null string.
+    SetDOMStringToNull(aDomain);
+  }
 
   return NS_OK;
 }