diff --git a/server/core/config.cc b/server/core/config.cc
index a0de7c547..0c2d9d68c 100644
--- a/server/core/config.cc
+++ b/server/core/config.cc
@@ -3156,6 +3156,15 @@ const char* param_type_to_str(const MXS_MODULE_PARAM* params, const char* name)
     return "<unknown parameter name>";
 }
 
+static bool wrong_protocol_type(const std::string& type, const std::string& protocol)
+{
+    bool have_server_proto = strcasecmp(protocol.c_str(), "mariadbbackend") == 0
+        || strcasecmp(protocol.c_str(), "mysqlbackend") == 0;
+    bool have_server_type = type == CN_SERVER;
+
+    return have_server_proto != have_server_type;
+}
+
 /**
  * @brief Check that the configuration objects have valid parameters
  *
@@ -3201,6 +3210,14 @@ static bool check_config_objects(CONFIG_CONTEXT* context)
             continue;
         }
 
+        // TODO: Separate the listener and server protocol objects, hard-coded checks are not good
+        if (wrong_protocol_type(type, obj->m_parameters.get_string(CN_PROTOCOL)))
+        {
+            MXS_ERROR("Wrong protocol module type for '%s'", obj->m_name.c_str());
+            rval = false;
+            continue;
+        }
+
         mxb_assert(param_set);
         std::vector<std::string> to_be_removed;
 
diff --git a/server/modules/routing/binlogrouter/blr_slave.cc b/server/modules/routing/binlogrouter/blr_slave.cc
index 25d93a04f..4b2613f21 100644
--- a/server/modules/routing/binlogrouter/blr_slave.cc
+++ b/server/modules/routing/binlogrouter/blr_slave.cc
@@ -4287,7 +4287,7 @@ int validate_connection_name(ROUTER_INSTANCE* router, const std::string& name, c
 
     int index = -1;
 
-    char custom_message[BINLOG_ERROR_MSG_LEN + 1];
+    char custom_message[BINLOG_ERROR_MSG_LEN];
 
     const char* message = DEFAULT_MESSAGE;