diff --git a/rcl/src/rcl/expand_topic_name.c b/rcl/src/rcl/expand_topic_name.c
index 142e04c4f..ace1bcde0 100644
--- a/rcl/src/rcl/expand_topic_name.c
+++ b/rcl/src/rcl/expand_topic_name.c
@@ -81,7 +81,7 @@ rcl_expand_topic_name(
     return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
   }
   if (validation_result != RMW_NODE_NAME_VALID) {
-    RCL_SET_ERROR_MSG("node name is invalid");
+    RCL_SET_ERROR_MSG(rmw_node_name_validation_result_string(validation_result));
     return RCL_RET_NODE_INVALID_NAME;
   }
   // validate the namespace
@@ -91,7 +91,7 @@ rcl_expand_topic_name(
     return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
   }
   if (validation_result != RMW_NODE_NAME_VALID) {
-    RCL_SET_ERROR_MSG("node namespace is invalid");
+    RCL_SET_ERROR_MSG(rmw_namespace_validation_result_string(validation_result));
     return RCL_RET_NODE_INVALID_NAMESPACE;
   }
   // check if the topic has substitutions to be made