diff --git a/car.c b/car.c
index 5568c59..b1cdcae 100644
--- a/car.c
+++ b/car.c
@@ -9,6 +9,14 @@
  */
 #include "car.h"
 
+struct CarData {
+  CarType type;
+  Color color;
+  double fill_level;
+  double acceleration_rate;
+  int speed;
+};
+
 Car get_car(CarType carType) {
     Car car = {carType, RED, 0.0, 0.0, 0};
     return car;
diff --git a/car.h b/car.h
index 09b462c..42ccbca 100644
--- a/car.h
+++ b/car.h
@@ -8,18 +8,13 @@
 * ----------------------------------------------------------
 */
 
-typedef struct CarImplementation* Car;
+#ifndef ___CAR_H
+#define ___CAR_H
+
+typedef struct CarData* Car;
 typedef enum { AIXAM, FIAT_MULTIPLA, JEEP } CarType;
 typedef enum { RED, GREEN, BLUE, ORANGE, SILVER, BLACK } Color;
 
-struct CarImplementation {
-  CarType type;
-  Color color;
-  double fill_level;
-  double acceleration_rate;
-  int speed;
-};
-
 Car get_car(CarType type);
 CarType get_type(Car car);
 Color get_color(Car car);
@@ -28,4 +23,6 @@ double get_acceleration_rate(Car car);
 int get_speed(Car car);
 void set_acceleration_rate(Car car, double acceleration_rate);
 void accelerate(Car car);
-void init();
\ No newline at end of file
+void init();
+
+#endif
\ No newline at end of file