diff --git a/monitor/hmp.c b/monitor/hmp.c
index 34e2b8f748..a3ee02e52c 100644
--- a/monitor/hmp.c
+++ b/monitor/hmp.c
@@ -577,10 +577,11 @@ static const char *get_command_name(const char *cmdline,
  * Read key of 'type' into 'key' and return the current
  * 'type' pointer.
  */
-static char *key_get_info(const char *type, char **key)
+static const char *key_get_info(const char *type, char **key)
 {
     size_t len;
-    char *p, *str;
+    const char *p;
+    char *str;
 
     if (*type == ',') {
         type++;