diff --git a/libraries/AP_Motors/AP_Motors.h b/libraries/AP_Motors/AP_Motors.h
index a13c351fcf..2a66949b97 100644
--- a/libraries/AP_Motors/AP_Motors.h
+++ b/libraries/AP_Motors/AP_Motors.h
@@ -1,7 +1,5 @@
 // -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
-
-#ifndef __AP_MOTORS_H__
-#define __AP_MOTORS_H__
+#pragma once
 
 #include "AP_Motors_Class.h"
 #include "AP_MotorsMulticopter.h"
@@ -15,5 +13,3 @@
 #include "AP_MotorsHeli_Single.h"
 #include "AP_MotorsSingle.h"
 #include "AP_MotorsCoax.h"
-
-#endif // __AP_MOTORS_H__
diff --git a/libraries/AP_Motors/AP_MotorsCoax.h b/libraries/AP_Motors/AP_MotorsCoax.h
index 68592d341f..b23aefa80c 100644
--- a/libraries/AP_Motors/AP_MotorsCoax.h
+++ b/libraries/AP_Motors/AP_MotorsCoax.h
@@ -2,9 +2,7 @@
 
 /// @file	AP_MotorsCoax.h
 /// @brief	Motor and Servo control class for Co-axial helicopters with two motors and two flaps
-
-#ifndef __AP_MOTORS_COAX_H__
-#define __AP_MOTORS_COAX_H__
+#pragma once
 
 #include <AP_Common/AP_Common.h>
 #include <AP_Math/AP_Math.h>        // ArduPilot Mega Vector/Matrix math Library
@@ -71,5 +69,3 @@ protected:
     RC_Channel&         _servo1;
     RC_Channel&         _servo2;
 };
-
-#endif  // AP_MOTORSCOAX
diff --git a/libraries/AP_Motors/AP_MotorsHeli.h b/libraries/AP_Motors/AP_MotorsHeli.h
index 52950303d0..fc3fa67882 100644
--- a/libraries/AP_Motors/AP_MotorsHeli.h
+++ b/libraries/AP_Motors/AP_MotorsHeli.h
@@ -2,9 +2,7 @@
 
 /// @file	AP_MotorsHeli.h
 /// @brief	Motor control class for Traditional Heli
-
-#ifndef __AP_MOTORS_HELI_H__
-#define __AP_MOTORS_HELI_H__
+#pragma once
 
 #include <inttypes.h>
 
@@ -246,5 +244,3 @@ protected:
     int16_t         _collective_range = 0;           // maximum absolute collective pitch range (500 - 1000)
     uint8_t         _servo_test_cycle_counter = 0;   // number of test cycles left to run after bootup
 };
-
-#endif  // AP_MOTORSHELI
diff --git a/libraries/AP_Motors/AP_MotorsHeli_RSC.h b/libraries/AP_Motors/AP_MotorsHeli_RSC.h
index f4f7c876d0..c5bdee42c5 100644
--- a/libraries/AP_Motors/AP_MotorsHeli_RSC.h
+++ b/libraries/AP_Motors/AP_MotorsHeli_RSC.h
@@ -1,7 +1,5 @@
 // -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
-
-#ifndef __AP_MOTORS_HELI_RSC_H__
-#define __AP_MOTORS_HELI_RSC_H__
+#pragma once
 
 #include <AP_Common/AP_Common.h>
 #include <AP_Math/AP_Math.h>            // ArduPilot Mega Vector/Matrix math Library
@@ -118,5 +116,3 @@ private:
     // write_rsc - outputs pwm onto output rsc channel. servo_out parameter is of the range 0 ~ 1000
     void            write_rsc(int16_t servo_out);
 };
-
-#endif // AP_MOTORS_HELI_RSC_H
diff --git a/libraries/AP_Motors/AP_MotorsHeli_Single.h b/libraries/AP_Motors/AP_MotorsHeli_Single.h
index e9588bd2ad..5522e56f1f 100644
--- a/libraries/AP_Motors/AP_MotorsHeli_Single.h
+++ b/libraries/AP_Motors/AP_MotorsHeli_Single.h
@@ -2,9 +2,7 @@
 
 /// @file	AP_MotorsHeli_Single.h
 /// @brief	Motor control class for traditional heli
-
-#ifndef __AP_MOTORS_HELI_SINGLE_H__
-#define __AP_MOTORS_HELI_SINGLE_H__
+#pragma once
 
 #include <AP_Common/AP_Common.h>
 #include <AP_Math/AP_Math.h>            // ArduPilot Mega Vector/Matrix math Library
@@ -186,5 +184,3 @@ protected:
 
     bool            _acro_tail = false;
 };
-
-#endif  // __AP_MOTORS_HELI_SINGLE_H__
diff --git a/libraries/AP_Motors/AP_MotorsHexa.h b/libraries/AP_Motors/AP_MotorsHexa.h
index 335d263385..134ad64c12 100644
--- a/libraries/AP_Motors/AP_MotorsHexa.h
+++ b/libraries/AP_Motors/AP_MotorsHexa.h
@@ -2,9 +2,7 @@
 
 /// @file	AP_MotorsHexa.h
 /// @brief	Motor control class for Hexacopters
-
-#ifndef __AP_MOTORS_HEXA_H__
-#define __AP_MOTORS_HEXA_H__
+#pragma once
 
 #include <AP_Common/AP_Common.h>
 #include <AP_Math/AP_Math.h>        // ArduPilot Mega Vector/Matrix math Library
@@ -26,5 +24,3 @@ public:
 protected:
 
 };
-
-#endif  // AP_MOTORSHEXA
diff --git a/libraries/AP_Motors/AP_MotorsMatrix.h b/libraries/AP_Motors/AP_MotorsMatrix.h
index dbd571b008..62933ef498 100644
--- a/libraries/AP_Motors/AP_MotorsMatrix.h
+++ b/libraries/AP_Motors/AP_MotorsMatrix.h
@@ -2,9 +2,7 @@
 
 /// @file	AP_MotorsMatrix.h
 /// @brief	Motor control class for Matrixcopters
-
-#ifndef __AP_MOTORS_MATRIX_H__
-#define __AP_MOTORS_MATRIX_H__
+#pragma once
 
 #include <AP_Common/AP_Common.h>
 #include <AP_Math/AP_Math.h>        // ArduPilot Mega Vector/Matrix math Library
@@ -79,5 +77,3 @@ protected:
     float               _yaw_factor[AP_MOTORS_MAX_NUM_MOTORS];  // each motors contribution to yaw (normally 1 or -1)
     uint8_t             _test_order[AP_MOTORS_MAX_NUM_MOTORS];  // order of the motors in the test sequence
 };
-
-#endif  // AP_MOTORSMATRIX
diff --git a/libraries/AP_Motors/AP_MotorsMulticopter.h b/libraries/AP_Motors/AP_MotorsMulticopter.h
index 632f8e4c90..3f96d4cdb4 100644
--- a/libraries/AP_Motors/AP_MotorsMulticopter.h
+++ b/libraries/AP_Motors/AP_MotorsMulticopter.h
@@ -2,9 +2,7 @@
 
 /// @file	AP_MotorsMulticopter.h
 /// @brief	Motor control class for Multicopters
-
-#ifndef __AP_MOTORS_MULTICOPTER_H__
-#define __AP_MOTORS_MULTICOPTER_H__
+#pragma once
 
 #include "AP_Motors_Class.h"
 
@@ -177,4 +175,3 @@ protected:
     float               _lift_max;              // maximum lift ratio from battery voltage
     float               _throttle_limit;        // ratio of throttle limit between hover and maximum
 };
-#endif  // __AP_MOTORS_MULTICOPTER_H__
diff --git a/libraries/AP_Motors/AP_MotorsOcta.h b/libraries/AP_Motors/AP_MotorsOcta.h
index d1b0cb40a1..858c0cf290 100644
--- a/libraries/AP_Motors/AP_MotorsOcta.h
+++ b/libraries/AP_Motors/AP_MotorsOcta.h
@@ -2,9 +2,7 @@
 
 /// @file	AP_MotorsOcta.h
 /// @brief	Motor control class for Octacopters
-
-#ifndef __AP_MOTORS_OCTA_H__
-#define __AP_MOTORS_OCTA_H__
+#pragma once
 
 #include <AP_Common/AP_Common.h>
 #include <AP_Math/AP_Math.h>        // ArduPilot Mega Vector/Matrix math Library
@@ -26,5 +24,3 @@ public:
 protected:
 
 };
-
-#endif  // AP_MOTORSOCTA
diff --git a/libraries/AP_Motors/AP_MotorsOctaQuad.h b/libraries/AP_Motors/AP_MotorsOctaQuad.h
index 50a3ce0c27..4c8e5f7556 100644
--- a/libraries/AP_Motors/AP_MotorsOctaQuad.h
+++ b/libraries/AP_Motors/AP_MotorsOctaQuad.h
@@ -2,9 +2,7 @@
 
 /// @file	AP_MotorsOctaQuad.h
 /// @brief	Motor control class for OctaQuadcopters
-
-#ifndef __AP_MOTORS_OCTA_QUAD_H__
-#define __AP_MOTORS_OCTA_QUAD_H__
+#pragma once
 
 #include <AP_Common/AP_Common.h>
 #include <AP_Math/AP_Math.h>        // ArduPilot Mega Vector/Matrix math Library
@@ -26,5 +24,3 @@ public:
 protected:
 
 };
-
-#endif  // AP_MOTORSOCTAQUAD
diff --git a/libraries/AP_Motors/AP_MotorsQuad.h b/libraries/AP_Motors/AP_MotorsQuad.h
index 394bdeeb89..3dfb0c7079 100644
--- a/libraries/AP_Motors/AP_MotorsQuad.h
+++ b/libraries/AP_Motors/AP_MotorsQuad.h
@@ -2,9 +2,7 @@
 
 /// @file	AP_MotorsQuad.h
 /// @brief	Motor control class for Quadcopters
-
-#ifndef __AP_MOTORS_QUAD_H__
-#define __AP_MOTORS_QUAD_H__
+#pragma once
 
 #include <AP_Common/AP_Common.h>
 #include <AP_Math/AP_Math.h>        // ArduPilot Mega Vector/Matrix math Library
@@ -26,5 +24,3 @@ public:
 protected:
 
 };
-
-#endif  // AP_MOTORSQUAD
diff --git a/libraries/AP_Motors/AP_MotorsSingle.h b/libraries/AP_Motors/AP_MotorsSingle.h
index 167e620710..8c830cec0f 100644
--- a/libraries/AP_Motors/AP_MotorsSingle.h
+++ b/libraries/AP_Motors/AP_MotorsSingle.h
@@ -2,9 +2,7 @@
 
 /// @file	AP_MotorsSingle.h
 /// @brief	Motor and Servo control class for Singlecopters
-
-#ifndef __AP_MOTORS_SING_H__
-#define __AP_MOTORS_SING_H__
+#pragma once
 
 #include <AP_Common/AP_Common.h>
 #include <AP_Math/AP_Math.h>        // ArduPilot Mega Vector/Matrix math Library
@@ -74,5 +72,3 @@ protected:
     RC_Channel&         _servo3;
     RC_Channel&         _servo4;
 };
-
-#endif  // AP_MOTORSSINGLE
diff --git a/libraries/AP_Motors/AP_MotorsTri.h b/libraries/AP_Motors/AP_MotorsTri.h
index 2699b60775..efc90017f5 100644
--- a/libraries/AP_Motors/AP_MotorsTri.h
+++ b/libraries/AP_Motors/AP_MotorsTri.h
@@ -2,9 +2,7 @@
 
 /// @file	AP_MotorsTri.h
 /// @brief	Motor control class for Tricopters
-
-#ifndef __AP_MOTORS_TRI_H__
-#define __AP_MOTORS_TRI_H__
+#pragma once
 
 #include <AP_Common/AP_Common.h>
 #include <AP_Math/AP_Math.h>        // ArduPilot Mega Vector/Matrix math Library
@@ -64,5 +62,3 @@ protected:
     AP_Int16        _yaw_servo_min;                     // Minimum angle limit of yaw servo
     AP_Int16        _yaw_servo_max;                     // Maximum angle limit of yaw servo
 };
-
-#endif  // AP_MOTORSTRI
diff --git a/libraries/AP_Motors/AP_MotorsY6.h b/libraries/AP_Motors/AP_MotorsY6.h
index d582246955..5b2b21a81e 100644
--- a/libraries/AP_Motors/AP_MotorsY6.h
+++ b/libraries/AP_Motors/AP_MotorsY6.h
@@ -2,9 +2,7 @@
 
 /// @file	AP_MotorsY6.h
 /// @brief	Motor control class for Y6 frames
-
-#ifndef __AP_MOTORS_Y6_H__
-#define __AP_MOTORS_Y6_H__
+#pragma once
 
 #include <AP_Common/AP_Common.h>
 #include <AP_Math/AP_Math.h>        // ArduPilot Mega Vector/Matrix math Library
@@ -28,5 +26,3 @@ public:
 protected:
 
 };
-
-#endif  // AP_MOTORSY6
diff --git a/libraries/AP_Motors/AP_Motors_Class.h b/libraries/AP_Motors/AP_Motors_Class.h
index 060b3e56db..d5e62d8f58 100644
--- a/libraries/AP_Motors/AP_Motors_Class.h
+++ b/libraries/AP_Motors/AP_Motors_Class.h
@@ -1,7 +1,5 @@
 // -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
-
-#ifndef __AP_MOTORS_CLASS_H__
-#define __AP_MOTORS_CLASS_H__
+#pragma once
 
 #include <AP_Common/AP_Common.h>
 #include <AP_Math/AP_Math.h>        // ArduPilot Mega Vector/Matrix math Library
@@ -169,4 +167,3 @@ protected:
     uint8_t             _motor_map[AP_MOTORS_MAX_NUM_MOTORS];
     uint16_t            _motor_map_mask;
 };
-#endif  // __AP_MOTORS_CLASS_H__