diff --git a/meson.build b/meson.build
index fd38923b0d..af7a914704 100644
--- a/meson.build
+++ b/meson.build
@@ -442,7 +442,8 @@ foreach ident : ['secure_getenv', '__secure_getenv']
 endforeach
 
 foreach ident : [
-        ['memfd_create',      '''#include <sys/memfd.h>'''],
+        ['memfd_create',      '''#define _GNU_SOURCE
+                                 #include <sys/mman.h>'''],
         ['gettid',            '''#include <sys/types.h>'''],
         ['pivot_root',        '''#include <stdlib.h>'''],     # no known header declares pivot_root
         ['name_to_handle_at', '''#define _GNU_SOURCE