diff --git a/spa/include/spa/support/system.h b/spa/include/spa/support/system.h
index dbd84f105..b821a9c08 100644
--- a/spa/include/spa/support/system.h
+++ b/spa/include/spa/support/system.h
@@ -29,6 +29,10 @@
 extern "C" {
 #endif
 
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
 #include <time.h>
 #include <sys/types.h>