diff --git a/keil_project/Services/DcMotor.h b/keil_project/Services/DcMotor.h
index d9f7771..34c690a 100644
--- a/keil_project/Services/DcMotor.h
+++ b/keil_project/Services/DcMotor.h
@@ -1,6 +1,9 @@
-//codé par Kévin Cavailles et Jasper Güldenstein
+#ifndef DC_MOTOR_H
+#define DC_MOTOR_H
 
 void DC_MOTOR_Init(void);
 
 // set a speed between -100 (full throttle clockwise) 0 (stop) and 100 (full throttle counterclockwise)
 void DC_MOTOR_SetSpeed(int speed);
+
+#endif
diff --git a/keil_project/Services/IncrEncoder.h b/keil_project/Services/IncrEncoder.h
index 7767b5e..dfa6662 100644
--- a/keil_project/Services/IncrEncoder.h
+++ b/keil_project/Services/IncrEncoder.h
@@ -1,7 +1,7 @@
-#ifndef INCR_ENCODER
+#ifndef INCR_ENCODER_H
+#define INCR_ENCODER_H
+
 
-/**
-  */
 void INCR_ENCODER_Init(void);
 
 int INCR_ENCODER_IsAbsolute(void);
diff --git a/keil_project/Services/RFInput.h b/keil_project/Services/RFInput.h
index 8b65495..8139834 100644
--- a/keil_project/Services/RFInput.h
+++ b/keil_project/Services/RFInput.h
@@ -1,5 +1,5 @@
-//codé par Kévin Cavailles et Jasper Güldenstein
-
+#ifndef RF_INPUT_H
+#define RF_INPUT_H
 
 // initializes the PWM input of the remote on PB6
 void RF_INPUT_Init(void);
@@ -12,3 +12,5 @@ int RF_INPUT_GetDutyTimeUs(void);
 
 // returns the duty time of the PWM signal of the remote as a value between -100 and 100
 int RF_INPUT_GetDutyTimeRelative(void);
+
+#endif
diff --git a/keil_project/Services/Sail.h b/keil_project/Services/Sail.h
index 687a6eb..26f8aee 100644
--- a/keil_project/Services/Sail.h
+++ b/keil_project/Services/Sail.h
@@ -1,6 +1,11 @@
 //codé par Kévin Cavailles et Jasper Güldenstein
 
+#ifndef SAIL_H
+#define SAIL_H
+
 void SAIL_Init(void);
 
 // sets the opening angle of the sail
-void SAIL_SetAngle(float angle);
\ No newline at end of file
+void SAIL_SetAngle(float angle);
+
+#endif
diff --git a/keil_project/Services/Servo.h b/keil_project/Services/Servo.h
index cf6748c..7d3f780 100644
--- a/keil_project/Services/Servo.h
+++ b/keil_project/Services/Servo.h
@@ -1,7 +1,5 @@
-#ifndef SERVO
-#define SERVO
-
-//codé par Kévin Cavailles et Jasper Güldenstein
+#ifndef SERVO_H
+#define SERVO_H
 
 void SERVO_Init(void);