--- a/js/src/ion/Ion.cpp
+++ b/js/src/ion/Ion.cpp
@@ -1265,17 +1265,17 @@ ion::CanEnterAtBranch(JSContext *cx, Han
     // Mark as forbidden if frame can't be handled.
     if (!CheckFrame(fp)) {
         ForbidCompilation(cx, script);
         return Method_CantCompile;
     }
 
     // Attempt compilation. Returns Method_Compiled if already compiled.
     JSFunction *fun = fp->isFunctionFrame() ? fp->fun() : NULL;
-    MethodStatus status = Compile(cx, script, fun, pc, false);
+    MethodStatus status = Compile(cx, script, fun, pc, fp->isConstructing());
     if (status != Method_Compiled) {
         if (status == Method_CantCompile)
             ForbidCompilation(cx, script);
         return status;
     }
 
     if (script->ion->osrPc() != pc)
         return Method_Skipped;