diff --git a/mailnews/mime/cthandlers/glue/nsMimeContentTypeHandler.cpp b/mailnews/mime/cthandlers/glue/nsMimeContentTypeHandler.cpp
index 45812565a8d..38333de77df 100644
--- a/mailnews/mime/cthandlers/glue/nsMimeContentTypeHandler.cpp
+++ b/mailnews/mime/cthandlers/glue/nsMimeContentTypeHandler.cpp
@@ -63,7 +63,7 @@ nsMimeContentTypeHandler::nsMimeContentTypeHandler(const char *aMimeType,
 nsMimeContentTypeHandler::~nsMimeContentTypeHandler(void)
 {
   if (mimeType) {
-    free(mimeType);
+    NS_Free(mimeType);
     mimeType = 0;
   }
   realCreateContentTypeHandlerClass = 0;