diff --git a/src/busctl/busctl-introspect.h b/src/busctl/busctl-introspect.h
index 1a045bea1d5..720a0df79a1 100644
--- a/src/busctl/busctl-introspect.h
+++ b/src/busctl/busctl-introspect.h
@@ -2,6 +2,7 @@
 #pragma once
 
 #include <stdbool.h>
+#include <stdint.h>
 
 typedef struct XMLIntrospectOps {
         int (*on_path)(const char *path, void *userdata);