diff --git a/driver_library/src/ethosu.cpp b/driver_library/src/ethosu.cpp
index 662fed7..16b9654 100644
--- a/driver_library/src/ethosu.cpp
+++ b/driver_library/src/ethosu.cpp
@@ -489,7 +489,7 @@
 
     // if timeout negative wait forever
     if (timeoutNanos < 0) {
-        return eppoll(&pfd, 1, NULL, NULL);
+        return eppoll(&pfd, 1, NULL, NULL) == 0;
     }
 
     struct timespec tmo_p;