diff --git a/mozilla/toolkit/xre/nsAppRunner.cpp b/mozilla/toolkit/xre/nsAppRunner.cpp
index 444ff83b89c..dd97c0a38aa 100644
--- a/mozilla/toolkit/xre/nsAppRunner.cpp
+++ b/mozilla/toolkit/xre/nsAppRunner.cpp
@@ -331,7 +331,8 @@ enum ArgResult {
 static void RemoveArg(char **argv)
 {
   do {
-    *argv = *(++argv);
+    *argv = *(argv + 1);
+    ++argv;
   } while (*argv);
 
   --gArgc;