diff --git a/src/kits/interface/ScrollBar.cpp b/src/kits/interface/ScrollBar.cpp
index 8d42d2ae2f..8ba3ed7730 100644
--- a/src/kits/interface/ScrollBar.cpp
+++ b/src/kits/interface/ScrollBar.cpp
@@ -85,7 +85,7 @@ public:
 	
 	status_t StartMessageRunner(BHandler *target, float value)
 	{
-		ASSERT(fMessageRunner == NULL);
+		ASSERT(fScrollRunner == NULL);
 		
 		BMessage message(B_VALUE_CHANGED);
 		message.AddFloat("value", value);