diff --git a/libraries/AP_Declination/AP_Declination.h b/libraries/AP_Declination/AP_Declination.h
index f3fbe439ae..e9507ecac6 100644
--- a/libraries/AP_Declination/AP_Declination.h
+++ b/libraries/AP_Declination/AP_Declination.h
@@ -1,4 +1,4 @@
-// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: t -*-
+// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
 
 #ifndef AP_Declination_h
 #define AP_Declination_h