--- a/toolkit/components/url-classifier/nsUrlClassifierUtils.cpp
+++ b/toolkit/components/url-classifier/nsUrlClassifierUtils.cpp
@@ -87,17 +87,18 @@ GetPlatformType()
   return ANDROID_PLATFORM;
 #elif defined(XP_MACOSX)
   return OSX_PLATFORM;
 #elif defined(XP_LINUX)
   return LINUX_PLATFORM;
 #elif defined(XP_WIN)
   return WINDOWS_PLATFORM;
 #else
-  return PLATFORM_TYPE_UNSPECIFIED;
+  // Default to Linux for other platforms (see bug 1362501).
+  return LINUX_PLATFORM;
 #endif
 }
 
 typedef FetchThreatListUpdatesRequest_ListUpdateRequest ListUpdateRequest;
 typedef FetchThreatListUpdatesRequest_ListUpdateRequest_Constraints Constraints;
 
 static void
 InitListUpdateRequest(ThreatType aThreatType,