diff --git a/js/src/jsinferinlines.h b/js/src/jsinferinlines.h
index 5c2005d3843..805ae9b38c2 100644
--- a/js/src/jsinferinlines.h
+++ b/js/src/jsinferinlines.h
@@ -703,7 +703,7 @@ UseNewTypeForClone(JSFunction *fun)
         return true;
 
     if (fun->isArrow())
-        return true;
+        return false;
 
     if (fun->hasSingletonType())
         return false;
diff --git a/js/src/jsscript.cpp b/js/src/jsscript.cpp
index ee887837bb0..bd5778f8b40 100644
--- a/js/src/jsscript.cpp
+++ b/js/src/jsscript.cpp
@@ -2425,6 +2425,7 @@ js::CloneScript(JSContext *cx, HandleObject enclosingScope, HandleFunction fun,
     dst->funNeedsDeclEnvObject = src->funNeedsDeclEnvObject;
     dst->funHasAnyAliasedFormal = src->funHasAnyAliasedFormal;
     dst->hasSingletons = src->hasSingletons;
+    dst->treatAsRunOnce = src->treatAsRunOnce;
     dst->isGenerator = src->isGenerator;
     dst->isGeneratorExp = src->isGeneratorExp;