diff --git a/test/v4l2_videodevice/buffer_cache.cpp b/test/v4l2_videodevice/buffer_cache.cpp
index d730e75..1870249 100644
--- a/test/v4l2_videodevice/buffer_cache.cpp
+++ b/test/v4l2_videodevice/buffer_cache.cpp
@@ -90,6 +90,11 @@ public:
 		/* Pick a hot buffer at random and store its index. */
 		int hotBuffer = dist(generator_);
 		int hotIndex = cache->get(*buffers[hotBuffer].get());
+		if (hotIndex < 0) {
+			std::cout << "Failed lookup from cache" << std::endl;
+			return TestFail;
+		}
+
 		cache->put(hotIndex);
 
 		/*