diff --git a/src/App.tsx b/src/App.tsx
index 9ac24e5..38afdb7 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -23,6 +23,7 @@ export default function App() {
                 onChange={(e: any) => setInput(e.target.value)}
                 value={input}
                 className="program"
+                spellCheck="false"
                 title={`\
 type Op =
     | number
@@ -168,7 +169,6 @@ function Stack({
 }): JSX.Element {
     let ns = [...state.stack];
     ns.reverse();
-    console.log(just_popped);
     let children = (just_popped ?? []).map((just_popped, i) => (
         <StackItem
             item={just_popped}
@@ -328,7 +328,7 @@ function step(state: State, op: Op): State {
     ns.jumped_from = ns.ip;
     ns.just_pushed = false;
     ns.just_swapped = false;
-    ns.just_popped = undefined;
+    ns.just_popped = [];
     ns.ip++;
 
     function binary_op(
@@ -399,15 +399,21 @@ function step(state: State, op: Op): State {
     if (ns.stack.length > state.stack.length) {
         ns.just_pushed = true;
     } else if (ns.stack.length < state.stack.length) {
-        ns.just_popped = state.stack.slice(ns.stack.length - 1).reverse();
-        if (state.stack.length - ns.stack.length == 1) {
+        if (is_binary(op)) {
+            ns.just_popped = state.stack.slice(-2).reverse();
             ns.just_pushed = true;
+        } else {
+            ns.just_popped = [state.stack[state.stack.length - 1]];
         }
     }
 
     return ns;
 }
 
+function is_binary(op: Op): op is "add" | "sub" | "div" | "mul" | "cmp" {
+    return ["add", "sub", "div", "mul", "cmp"].indexOf(`${op}`) >= 0;
+}
+
 function cmp(a: number, b: number): number {
     if (a < b) {
         return -1;