diff --git a/mozilla/xpcom/threads/nsProcessCommon.cpp b/mozilla/xpcom/threads/nsProcessCommon.cpp
index d54094f883c..0fb8eb13fe1 100644
--- a/mozilla/xpcom/threads/nsProcessCommon.cpp
+++ b/mozilla/xpcom/threads/nsProcessCommon.cpp
@@ -352,6 +352,9 @@ nsProcess::Run(PRBool blocking, const char **args, PRUint32 count, PRUint32 *pid
     if (err != noErr) {
         rv = PR_FAILURE;
     }
+
+    mExitValue = err;
+
 #else
     if ( blocking ) {
         mProcess = PR_CreateProcess(mTargetPath.get(), my_argv, NULL, NULL);