diff --git a/js/src/jsxdrapi.cpp b/js/src/jsxdrapi.cpp
index d63f24c6f91f..9702e377569d 100644
--- a/js/src/jsxdrapi.cpp
+++ b/js/src/jsxdrapi.cpp
@@ -695,6 +695,9 @@ JS_XDRFunctionObject(JSXDRState *xdr, JSObject **objp)
         fstate.filename = fun->script()->filename;
     }
 
+    if (!JS_XDRCStringOrNull(xdr, (char **) &fstate.filename))
+        return false;
+
     return js_XDRFunctionObject(xdr, objp);
 }