diff --git a/src/core/util/libxlio.h b/src/core/util/libxlio.h
index 98a569c6d..5eec1dc3c 100644
--- a/src/core/util/libxlio.h
+++ b/src/core/util/libxlio.h
@@ -70,7 +70,7 @@ typedef enum {
     TRANS_DEFAULT
 } transport_t;
 
-typedef enum { PROTO_UNDEFINED, PROTO_UDP, PROTO_TCP, PROTO_ALL } in_protocol_t;
+typedef enum : uint16_t { PROTO_UNDEFINED, PROTO_UDP, PROTO_TCP, PROTO_ALL } in_protocol_t;
 
 typedef enum { DEV_CLONE, DEV_REPLACE } dev_conf_mode_t;