diff --git a/src/libcharon/config/child_cfg.c b/src/libcharon/config/child_cfg.c
index ba35a086a..a33502eff 100644
--- a/src/libcharon/config/child_cfg.c
+++ b/src/libcharon/config/child_cfg.c
@@ -17,6 +17,8 @@
 
 #include "child_cfg.h"
 
+#include <stdint.h>
+
 #include <daemon.h>
 
 ENUM(action_names, ACTION_NONE, ACTION_RESTART,