diff --git a/controller_manager/test/test_controller/test_controller.hpp b/controller_manager/test/test_controller/test_controller.hpp
index 1b070ab302..f73f592037 100644
--- a/controller_manager/test/test_controller/test_controller.hpp
+++ b/controller_manager/test/test_controller/test_controller.hpp
@@ -65,7 +65,7 @@ class TestController : public controller_interface::ControllerInterface
   CONTROLLER_MANAGER_PUBLIC
   void set_state_interface_configuration(const controller_interface::InterfaceConfiguration & cfg);
 
-  size_t internal_counter = 0;
+  unsigned int internal_counter = 0;
   bool simulate_cleanup_failure = false;
   // Variable where we store when cleanup was called, pointer because the controller
   // is usually destroyed after cleanup