diff --git a/src/action.c b/src/action.c
index c2a0566c..0e5d181f 100644
--- a/src/action.c
+++ b/src/action.c
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0-only
+#define _POSIX_C_SOURCE
 #include <strings.h>
 #include <wlr/util/log.h>
 #include <signal.h>