diff --git a/src/bitcode.ts b/src/bitcode.ts
index 690287e..7ef6649 100644
--- a/src/bitcode.ts
+++ b/src/bitcode.ts
@@ -19,8 +19,8 @@ export class Builder {
     return new types.Void();
   }
 
-  public static i(width: number): types.Int {
-    return new types.Int(width);
+  public static i(width: number, signed: boolean = false): types.Int {
+    return new types.Int(width, signed);
   }
 
   public static signature(returnType: Type, params: Type[]): types.Signature {
diff --git a/src/types/int.ts b/src/types/int.ts
index 6c5bd54..9076c24 100644
--- a/src/types/int.ts
+++ b/src/types/int.ts
@@ -2,7 +2,7 @@ import * as values from '../values';
 import { Type } from './base';
 
 export class Int extends Type {
-  constructor(public readonly width: number) {
+  constructor(public readonly width: number, public readonly signed: boolean = false) {
     super('i' + width);
   }
 
@@ -16,7 +16,7 @@ export class Int extends Type {
     }
 
     const toInt = to as Int;
-    return toInt.width === this.width;
+    return toInt.width === this.width && toInt.signed === this.signed;
   }
 
   public val(num: number): values.constants.Int {