diff --git a/core/object/object.cpp b/core/object/object.cpp
index 2753b29b29f..41108bacbbc 100644
--- a/core/object/object.cpp
+++ b/core/object/object.cpp
@@ -978,7 +978,9 @@ String Object::to_string() {
 		String ret;
 		GDExtensionBool is_valid;
 		_extension->to_string(_extension_instance, &is_valid, &ret);
-		return ret;
+		if (is_valid) {
+			return ret;
+		}
 	}
 	return "<" + get_class() + "#" + itos(get_instance_id()) + ">";
 }
diff --git a/scene/main/node.cpp b/scene/main/node.cpp
index 59062228e70..5217e682bf6 100644
--- a/scene/main/node.cpp
+++ b/scene/main/node.cpp
@@ -2864,7 +2864,9 @@ String Node::to_string() {
 		String ret;
 		GDExtensionBool is_valid;
 		_get_extension()->to_string(_get_extension_instance(), &is_valid, &ret);
-		return ret;
+		if (is_valid) {
+			return ret;
+		}
 	}
 	return (get_name() ? String(get_name()) + ":" : "") + Object::to_string();
 }