diff --git a/test/Concurrent.cpp b/test/Concurrent.cpp
index 0694934..aeea17f 100644
--- a/test/Concurrent.cpp
+++ b/test/Concurrent.cpp
@@ -110,6 +110,7 @@
     ALOGI("ConcurrentExecute: waiting for callbacks");
     for (size_t i = 0; i < maxRequests; ++i)
     {
+        ARMNN_ASSERT(cb[i]);
         cb[i]->wait();
     }