diff --git a/kernel/marker.c b/kernel/marker.c
index 139260e5460c8158219293f8875734bfff642ce2..b5a9fe1d50d5ce1c480ca7ca1777e55e6deb485e 100644
--- a/kernel/marker.c
+++ b/kernel/marker.c
@@ -29,7 +29,7 @@ extern struct marker __start___markers[];
 extern struct marker __stop___markers[];
 
 /* Set to 1 to enable marker debug output */
-const int marker_debug;
+static const int marker_debug;
 
 /*
  * markers_mutex nests inside module_mutex. Markers mutex protects the builtin