diff --git a/src/interpreter/builtins.ts b/src/interpreter/builtins.ts
index 16322f1..433139a 100644
--- a/src/interpreter/builtins.ts
+++ b/src/interpreter/builtins.ts
@@ -12,10 +12,7 @@ const addUnaryIntegerOperationsTo = (env: Environment) => {
     },
   ];
 
-  for (const { name, fn } of [
-    { name: '~', fn: (a: number) => ~a },
-    { name: '!', fn: (a: number) => (!a ? 1 : 0) },
-  ]) {
+  for (const { name, fn } of [{ name: '~', fn: (a: number) => ~a }]) {
     env.set(name, {
       type: 'function',
       value: {