diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h
index 6ad2b5e..80bfdaa 100644
--- a/tools/perf/util/util.h
+++ b/tools/perf/util/util.h
@@ -39,6 +39,8 @@
 
 #define _ALL_SOURCE 1
 #define _BSD_SOURCE 1
+/* glibc 2.20 deprecates _BSD_SOURCE in favour of _DEFAULT_SOURCE */
+#define _DEFAULT_SOURCE 1
 #define HAS_BOOL
 
 #include <unistd.h>