diff --git src/openpa/test/opa_test.h src/openpa/test/opa_test.h
index 490b916..ec9c7f5 100644
--- src/openpa/test/opa_test.h
+++ src/openpa/test/opa_test.h
@@ -20,6 +20,7 @@
 #include <limits.h>
 #include <time.h>
 #if defined(OPA_HAVE_PTHREAD_H)
+#  define GNU_SOURCE
 #  include <pthread.h>
 #endif /* HAVE_PTHREAD_H */