diff --git a/js/src/vm/Debugger.cpp b/js/src/vm/Debugger.cpp
index 49108401a589..aa6090e01cd6 100644
--- a/js/src/vm/Debugger.cpp
+++ b/js/src/vm/Debugger.cpp
@@ -1571,10 +1571,7 @@ Debugger::onSingleStep(JSContext *cx, MutableHandleValue vp)
                 }
             }
         }
-        if (trappingScript->compileAndGo())
-            MOZ_ASSERT(stepperCount == trappingScript->stepModeCount());
-        else
-            MOZ_ASSERT(stepperCount <= trappingScript->stepModeCount());
+        MOZ_ASSERT(stepperCount == trappingScript->stepModeCount());
     }
 #endif