diff --git a/crates/ide/src/ty/infer.rs b/crates/ide/src/ty/infer.rs
index 55733f0..f146cc3 100644
--- a/crates/ide/src/ty/infer.rs
+++ b/crates/ide/src/ty/infer.rs
@@ -208,7 +208,8 @@ impl<'db> InferCtx<'db> {
                 self.infer_expr(body)
             }
             &Expr::IfThenElse(cond, then, else_) => {
-                self.infer_expr(cond);
+                let cond_ty = self.infer_expr(cond);
+                self.unify_kind(cond_ty, TyKind::Bool);
                 let then_ty = self.infer_expr(then);
                 let else_ty = self.infer_expr(else_);
                 self.unify(then_ty, else_ty);
diff --git a/crates/ide/src/ty/tests.rs b/crates/ide/src/ty/tests.rs
index 5aecd11..975d67b 100644
--- a/crates/ide/src/ty/tests.rs
+++ b/crates/ide/src/ty/tests.rs
@@ -102,6 +102,7 @@ fn recursive() {
 
 #[test]
 fn if_then_else() {
+    check("a: if a then 1 else 1", expect!["bool → int"]);
     check(
         "if 1 == 2 then { a = 1; } else { b = 1; }",
         expect!["{ a: int, b: int }"],