diff --git a/userspace/falco/app/actions/list_plugins.cpp b/userspace/falco/app/actions/list_plugins.cpp
index 3587c8ee..28bfd915 100644
--- a/userspace/falco/app/actions/list_plugins.cpp
+++ b/userspace/falco/app/actions/list_plugins.cpp
@@ -38,6 +38,6 @@ falco::app::run_result falco::app::actions::list_plugins(const falco::app::state
 		os << std::endl;
 	}
 
-	printf("%lu Plugins Loaded:\n\n%s\n", configs.size(), os.str().c_str());
+	printf("%zu Plugins Loaded:\n\n%s\n", configs.size(), os.str().c_str());
 	return run_result::exit();
 }