diff --git a/src/plugin_debug.c b/src/plugin_debug.c
index 13162b87..8918c39b 100644
--- a/src/plugin_debug.c
+++ b/src/plugin_debug.c
@@ -45,7 +45,7 @@ void print_col(struct mosquitto *client)
 int mosquitto_auth_plugin_version(void)
 {
 	printf(ANSI_BLUE "PLUGIN ::: mosquitto_auth_plugin_version()" ANSI_RESET "\n");
-	return MOSQ_AUTH_PLUGIN_VERSION;
+	return 4;
 }
 
 int mosquitto_auth_plugin_init(void **user_data, struct mosquitto_opt *auth_opts, int auth_opt_count)
diff --git a/src/plugin_defer.c b/src/plugin_defer.c
index 4ef34d01..2160a5df 100644
--- a/src/plugin_defer.c
+++ b/src/plugin_defer.c
@@ -24,7 +24,7 @@ Contributors:
 
 int mosquitto_auth_plugin_version(void)
 {
-	return MOSQ_AUTH_PLUGIN_VERSION;
+	return 4;
 }
 
 int mosquitto_auth_plugin_init(void **user_data, struct mosquitto_opt *auth_opts, int auth_opt_count)
@@ -47,18 +47,18 @@ int mosquitto_auth_security_cleanup(void *user_data, struct mosquitto_opt *auth_
 	return MOSQ_ERR_SUCCESS;
 }
 
-int mosquitto_auth_acl_check(void *user_data, int access, const struct mosquitto *client, struct mosquitto_acl_msg *msg)
+int mosquitto_auth_acl_check(void *user_data, int access, struct mosquitto *client, const struct mosquitto_acl_msg *msg)
 {
 	printf("mosquitto_acl_check(u:%s)\n", mosquitto_client_username(client));
 	return MOSQ_ERR_PLUGIN_DEFER;
 }
 
-int mosquitto_auth_unpwd_check(void *user_data, const struct mosquitto *client, const char *username, const char *password)
+int mosquitto_auth_unpwd_check(void *user_data, struct mosquitto *client, const char *username, const char *password)
 {
 	return MOSQ_ERR_PLUGIN_DEFER;
 }
 
-int mosquitto_auth_psk_key_get(void *user_data, const struct mosquitto *client, const char *hint, const char *identity, char *key, int max_key_len)
+int mosquitto_auth_psk_key_get(void *user_data, struct mosquitto *client, const char *hint, const char *identity, char *key, int max_key_len)
 {
 	return MOSQ_ERR_PLUGIN_DEFER;
 }