diff --git a/libs/libc/spawn/lib_psa_dump.c b/libs/libc/spawn/lib_psa_dump.c
index bbacdd05dc..da55cfb506 100644
--- a/libs/libc/spawn/lib_psa_dump.c
+++ b/libs/libc/spawn/lib_psa_dump.c
@@ -49,6 +49,7 @@
 #define CONFIG_DEBUG_INFO 1
 
 #include <spawn.h>
+#include <stdint.h>
 #include <debug.h>
 
 #ifdef CONFIG_DEBUG_FEATURES
@@ -129,7 +130,7 @@ void posix_spawnattr_dump(posix_spawnattr_t *attr)
       _err("            Unrecognized\n");
     }
 
-  _err("  sigmask:  %08x\n", attr->sigmask);
+  _err("  sigmask:  %08jx\n", (uintmax_t)attr->sigmask);
 #endif /* CONFIG_DEBUG_ERROR */
 }