diff --git a/Sources/Swift2dCar/Servo.swift b/Sources/Swift2dCar/Servo.swift
index 8f1c1a3..0cf2128 100644
--- a/Sources/Swift2dCar/Servo.swift
+++ b/Sources/Swift2dCar/Servo.swift
@@ -28,7 +28,7 @@ public protocol Servo {
     func detach()
 }
 
-public class PWMHardwareServo : Servo{
+open class PWMHardwareServo : Servo{
     private (set) var frameWidth : Float
     private var minDc: Float
     private var dcRange: Float
diff --git a/Sources/Swift2dCar/Vehicle.swift b/Sources/Swift2dCar/Vehicle.swift
index fa05ec6..44e3b12 100644
--- a/Sources/Swift2dCar/Vehicle.swift
+++ b/Sources/Swift2dCar/Vehicle.swift
@@ -14,7 +14,7 @@ public protocol Vehicle2D{
     var steering: Float {get set}
 }
 
-class MockVehicle: Vehicle2D {
+public class MockVehicle: Vehicle2D {
     public var throttle: Float = 0
     public var steering: Float = 0
 }
@@ -42,7 +42,7 @@ open class RPiVehicle2D: Vehicle2D{
         }
     }
     
-    init(withThrottlePin: Servo, withSteeringPin: Servo){
+    public init(withThrottlePin: Servo, withSteeringPin: Servo){
         pwmThrottle = withThrottlePin
         pwmSteering = withSteeringPin
     }