diff --git a/src/p_mach.h b/src/p_mach.h
index 8aebac17..bf25ee10 100644
--- a/src/p_mach.h
+++ b/src/p_mach.h
@@ -1405,7 +1405,7 @@ struct routines_command_64 {
 struct uuid_command {
     upx_uint32_t cmd;
     upx_uint32_t cmdsize;
-    uint8_t uuid[16];
+    upx_uint8_t uuid[16];
 };
 struct version_min_command {
     upx_uint32_t cmd;