diff --git a/libraries/AP_Limits/AP_Limit_Altitude.h b/libraries/AP_Limits/AP_Limit_Altitude.h
index dd143d71cc..95191cf9dc 100644
--- a/libraries/AP_Limits/AP_Limit_Altitude.h
+++ b/libraries/AP_Limits/AP_Limit_Altitude.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 -*-
 
 /// @file	limits.h
 /// @brief	Imposes limits on location (geofence), altitude and other parameters.
diff --git a/libraries/AP_Limits/AP_Limit_GPSLock.h b/libraries/AP_Limits/AP_Limit_GPSLock.h
index f8fb4d9204..db3c4677ad 100644
--- a/libraries/AP_Limits/AP_Limit_GPSLock.h
+++ b/libraries/AP_Limits/AP_Limit_GPSLock.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 -*-
 
 /// @file	limits.h
 /// @brief	Imposes limits on location (geofence), altitude and other parameters.
diff --git a/libraries/AP_Limits/AP_Limit_Geofence.h b/libraries/AP_Limits/AP_Limit_Geofence.h
index ab2a2f30c6..dd0a758d6c 100644
--- a/libraries/AP_Limits/AP_Limit_Geofence.h
+++ b/libraries/AP_Limits/AP_Limit_Geofence.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 -*-
 
 /// @file	limits.h
 /// @brief	Imposes limits on location (geofence), altitude and other parameters.
diff --git a/libraries/AP_Limits/AP_Limits.h b/libraries/AP_Limits/AP_Limits.h
index a6fcdee043..41a0f492e8 100644
--- a/libraries/AP_Limits/AP_Limits.h
+++ b/libraries/AP_Limits/AP_Limits.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 -*-
 
 /// @brief Imposes limits on location (geofence), altitude and other parameters.
 /// Each breach will trigger an action or set of actions to recover.