diff --git a/src/protocol/eval/executor.rs b/src/protocol/eval/executor.rs
index 75c41c08a68920931792d388ed51c4c5cdb16cb6..fe43edfd8207faf5e777a0eb40d607093c617812 100644
--- a/src/protocol/eval/executor.rs
+++ b/src/protocol/eval/executor.rs
@@ -825,8 +825,13 @@ impl Prompt {
             Statement::Local(stmt) => {
                 match stmt {
                     LocalStatement::Memory(stmt) => {
-                        let variable = &heap[stmt.variable];
-                        self.store.write(ValueId::Stack(variable.unique_id_in_scope as u32), Value::Unassigned);
+                        if cfg!(debug_assertions) {
+                            let variable = &heap[stmt.variable];
+                            debug_assert!(match self.store.read_ref(ValueId::Stack(variable.unique_id_in_scope as u32)) {
+                                Value::Unassigned => false,
+                                _ => true,
+                            });
+                        }
 
                         cur_frame.position = stmt.next;
                         Ok(EvalContinuation::Stepping)
@@ -1049,6 +1054,16 @@ impl Prompt {
             let stmt = &heap[cur_frame.position];
 
             match stmt {
+                Statement::Local(stmt) => {
+                    if let LocalStatement::Memory(stmt) = stmt {
+                        // Setup as unassigned, when we execute the memory
+                        // statement (after evaluating expression), it should no
+                        // longer be `Unassigned`.
+                        let variable = &heap[stmt.variable];
+                        self.store.write(ValueId::Stack(variable.unique_id_in_scope as u32), Value::Unassigned);
+                        cur_frame.prepare_single_expression(heap, stmt.initial_expr.upcast());
+                    }
+                },
                 Statement::If(stmt) => cur_frame.prepare_single_expression(heap, stmt.test),
                 Statement::While(stmt) => cur_frame.prepare_single_expression(heap, stmt.test),
                 Statement::Return(stmt) => {