diff --git a/toolkit/components/url-classifier/nsUrlClassifierUtils.cpp b/toolkit/components/url-classifier/nsUrlClassifierUtils.cpp
index 035e9d6bec53..d478725d7605 100644
--- a/toolkit/components/url-classifier/nsUrlClassifierUtils.cpp
+++ b/toolkit/components/url-classifier/nsUrlClassifierUtils.cpp
@@ -91,7 +91,7 @@ GetPlatformType()
 #elif defined(XP_WIN)
   return WINDOWS_PLATFORM;
 #else
-  #error Unrecognized platform type.
+  return PLATFORM_TYPE_UNSPECIFIED;
 #endif
 }