diff --git a/TECHDEBT.md b/TECHDEBT.md
index 555cbb8..efa397a 100644
--- a/TECHDEBT.md
+++ b/TECHDEBT.md
@@ -1,18 +1,4 @@
 # TODO
-- [ ] Reorder Responsibilities
-  - [ ] long class
-  - [ ] feature envy
-  - [ ] inappropriate intimacy
-  - [ ] data class
-  - [ ] message chain
-
-# Mikado
-- [ ] Change var to val (immutable)
-  - [x] Rover.turnLeft use copy() on state
-  - [x] Rover.turnRight use copy() on state
-  - [x] Rover.move use copy() on state
-  - [x] Rover.constructor use copy() on state
-    - [x] Change RoverState to Data Class
 
 # RPP
 - [ ] Refine Abstractions
@@ -35,7 +21,13 @@
 - [x] Complexity
   - [x] long method
   - [x] duplicated code
-  -
+- [x] Reorder Responsibilities
+  - [x] long class
+  - [x] feature envy
+  - [x] inappropriate intimacy
+  - [x] data class
+  - [x] message chain
+
 # Mikado
 - [x] Clean up constants and private fields
   - [x] Move move() into Heading.move(Position)
@@ -48,3 +40,9 @@
         - [x] state.heading in Rover.constructor to enum
           - [x] Change heading Char in RoverState to Heading enum
             - [x] Create Heading enum
+- [x] Change var to val (immutable)
+  - [x] Rover.turnLeft use copy() on state
+  - [x] Rover.turnRight use copy() on state
+  - [x] Rover.move use copy() on state
+  - [x] Rover.constructor use copy() on state
+    - [x] Change RoverState to Data Class
diff --git a/src/main/kotlin/org/example/Rover.kt b/src/main/kotlin/org/example/Rover.kt
index 4a81f94..79ba25b 100644
--- a/src/main/kotlin/org/example/Rover.kt
+++ b/src/main/kotlin/org/example/Rover.kt
@@ -17,27 +17,16 @@ class Rover {
 
     fun go(instructions: String) {
         for (instruction in instructions) {
-            when (instruction) {
-                COMMAND_TURN_LEFT -> turnLeft()
-                COMMAND_TURN_RIGHT -> turnRight()
-                COMMAND_MOVE -> move()
-            }
+            state =
+                when (instruction) {
+                    COMMAND_TURN_LEFT -> state.turnLeft()
+                    COMMAND_TURN_RIGHT -> state.turnRight()
+                    COMMAND_MOVE -> state.move()
+                    else -> state
+                }
         }
     }
 
-    private fun move() {
-        val (updatedX, updatedY) = state.heading.move(state.positionX, state.positionY)
-        state = state.copy(positionX = updatedX, positionY = updatedY)
-    }
-
-    private fun turnRight() {
-        state = state.copy(heading = state.heading.turnRight())
-    }
-
-    private fun turnLeft() {
-        state = state.copy(heading = state.heading.turnLeft())
-    }
-
     val position: String
         get() = "${state.positionX} ${state.positionY} ${state.heading}"
 
diff --git a/src/main/kotlin/org/example/RoverState.kt b/src/main/kotlin/org/example/RoverState.kt
index ba4fe98..18f63a5 100644
--- a/src/main/kotlin/org/example/RoverState.kt
+++ b/src/main/kotlin/org/example/RoverState.kt
@@ -4,4 +4,13 @@ data class RoverState(
     val positionX: Int = 0,
     val positionY: Int = 0,
     var heading: Heading = Heading.NORTH,
-)
+) {
+    fun turnLeft(): RoverState = copy(heading = heading.turnLeft())
+
+    fun turnRight(): RoverState = copy(heading = heading.turnRight())
+
+    fun move(): RoverState {
+        val (newX, newY) = heading.move(positionX, positionY)
+        return copy(positionX = newX, positionY = newY)
+    }
+}