diff --git a/plugins/dynamic-security/plugin.c b/plugins/dynamic-security/plugin.c
index 3ff1054a..980a3415 100644
--- a/plugins/dynamic-security/plugin.c
+++ b/plugins/dynamic-security/plugin.c
@@ -452,7 +452,7 @@ void dynsec__config_save(void)
 
 	/* Save to file */
 	file_path_len = strlen(config_file) + 1;
-	file_path = mosquitto_malloc(file_path_len);
+	file_path = mosquitto_malloc(file_path_len + 4);
 	if(file_path == NULL){
 		mosquitto_free(json_str);
 		mosquitto_log_printf(MOSQ_LOG_ERR, "Error saving Dynamic security plugin config: Out of memory.\n");