diff --git a/lib/miniImp.ml b/lib/miniImp.ml
index 6a8e507..afa9ea3 100644
--- a/lib/miniImp.ml
+++ b/lib/miniImp.ml
@@ -49,7 +49,10 @@ Random.self_init ()
 let rec evaluate (mem: memory) (command: c_exp) =
   match command with
     Skip -> mem
-  | Assignment (v, exp_a) -> {assignments = VariableMap.add v (evaluate_a mem exp_a) mem.assignments}
+  | Assignment (v, exp_a) -> {
+      (* Map.add replaces the previeus value *)
+      assignments = VariableMap.add v (evaluate_a mem exp_a) mem.assignments
+    }
   | Sequence (exp_c1, exp_c2) -> (
       let mem2 = evaluate mem exp_c1 in
       evaluate mem2 exp_c2