diff --git a/gio/gdbus-2.0/codegen/codegen.py b/gio/gdbus-2.0/codegen/codegen.py
index 3fe2382ac..75fbff2e9 100644
--- a/gio/gdbus-2.0/codegen/codegen.py
+++ b/gio/gdbus-2.0/codegen/codegen.py
@@ -37,7 +37,7 @@ class CodeGenerator:
         self.h = h
         self.c = c
         self.namespace = namespace
-        if len(namespace) > 1:
+        if len(namespace) > 0:
             self.ns_upper = utils.camel_case_to_uscore(namespace).upper() + '_'
             self.ns_lower = utils.camel_case_to_uscore(namespace).lower() + '_'
         else: