diff --git a/drd/tests/thread_name.c b/drd/tests/thread_name.c
index f71f19f..98c7bb8 100644
--- a/drd/tests/thread_name.c
+++ b/drd/tests/thread_name.c
@@ -1,6 +1,6 @@
 /* Test whether assigning names to threads works properly. */
 
-
+#define _GNU_SOURCE
 #include <pthread.h>
 #include <stddef.h>
 #include <stdio.h>