Suppress compiler warning about memmem on Linux
diff --git a/src/plist.c b/src/plist.c
index f58148b..2d5042e 100644
--- a/src/plist.c
+++ b/src/plist.c
@@ -25,6 +25,7 @@
 #include <config.h>
 #endif
 
+#define _GNU_SOURCE 1
 #include <string.h>
 #include "plist.h"
 #include <stdlib.h>