diff --git a/tock_support_cppcsp.h b/tock_support_cppcsp.h
index 7202931..1117a1e 100644
--- a/tock_support_cppcsp.h
+++ b/tock_support_cppcsp.h
@@ -370,7 +370,7 @@ public:
 	inline void operator=(const tockSendableArrayOfBytes& _src)
 	{
 		//We use the receiver's byte count:
-		memcpy(dp,sp,n);
+		memcpy(dp,_src.sp,n);
 	}
 };