diff --git a/src/plugins/valgrind/memcheck/memcheckrunner.cpp b/src/plugins/valgrind/memcheck/memcheckrunner.cpp
index 8029c7b847229bd141f7efc6e5a5e58bd881631e..81a91005d06455fc5223a257c8dcc42d87a19839 100644
--- a/src/plugins/valgrind/memcheck/memcheckrunner.cpp
+++ b/src/plugins/valgrind/memcheck/memcheckrunner.cpp
@@ -168,6 +168,7 @@ void MemcheckRunner::logSocketConnected()
 
 void MemcheckRunner::readLogSocket()
 {
+    QTC_ASSERT(d->logSocket, return);
     emit logMessageReceived(d->logSocket->readAll());
 }