diff --git a/compiler/can/src/builtins.rs b/compiler/can/src/builtins.rs
index 51cc825539..c4fcf9544f 100644
--- a/compiler/can/src/builtins.rs
+++ b/compiler/can/src/builtins.rs
@@ -32,9 +32,57 @@ pub fn builtin_defs(var_store: &VarStore) -> Vec<Def> {
         int_div(var_store),
         int_abs(var_store),
         int_rem(var_store),
+        int_is_odd(var_store),
+        int_is_even(var_store),
     ]
 }
 
+/// Int.isOdd : Int -> Bool
+fn int_is_odd(var_store: &VarStore) -> Def {
+    use crate::expr::Expr::*;
+
+    defn(
+        Symbol::INT_IS_ODD,
+        vec![Symbol::INT_IS_ODD_ARG],
+        var_store,
+        call(
+            Symbol::INT_EQ_I64,
+            vec![
+                call(
+                    Symbol::INT_REM_UNSAFE,
+                    vec![Var(Symbol::INT_IS_ODD_ARG), Int(var_store.fresh(), 2)],
+                    var_store,
+                ),
+                Int(var_store.fresh(), 1),
+            ],
+            var_store,
+        ),
+    )
+}
+
+/// Int.isEven : Int -> Bool
+fn int_is_even(var_store: &VarStore) -> Def {
+    use crate::expr::Expr::*;
+
+    defn(
+        Symbol::INT_IS_EVEN,
+        vec![Symbol::INT_IS_EVEN_ARG],
+        var_store,
+        call(
+            Symbol::INT_EQ_I64,
+            vec![
+                call(
+                    Symbol::INT_REM_UNSAFE,
+                    vec![Var(Symbol::INT_IS_EVEN_ARG), Int(var_store.fresh(), 2)],
+                    var_store,
+                ),
+                Int(var_store.fresh(), 0),
+            ],
+            var_store,
+        ),
+    )
+}
+
 /// List.get : List elem, Int -> Result elem [ OutOfBounds ]*
 fn list_get(var_store: &VarStore) -> Def {
     use crate::expr::Expr::*;
diff --git a/compiler/gen/tests/gen_builtins.rs b/compiler/gen/tests/gen_builtins.rs
index cff3b2def5..dd9b928612 100644
--- a/compiler/gen/tests/gen_builtins.rs
+++ b/compiler/gen/tests/gen_builtins.rs
@@ -257,6 +257,18 @@ mod gen_builtins {
         );
     }
 
+    #[test]
+    fn gen_is_odd() {
+        assert_evals_to!("Int.isOdd 4", false, bool);
+        assert_evals_to!("Int.isOdd 5", true, bool);
+    }
+
+    #[test]
+    fn gen_is_even() {
+        assert_evals_to!("Int.isEven 6", true, bool);
+        assert_evals_to!("Int.isEven 7", false, bool);
+    }
+
     #[test]
     fn lt_i64() {
         assert_evals_to!("1 < 2", true, bool);
diff --git a/compiler/module/src/symbol.rs b/compiler/module/src/symbol.rs
index 5b48f5c23e..efc2819356 100644
--- a/compiler/module/src/symbol.rs
+++ b/compiler/module/src/symbol.rs
@@ -615,6 +615,10 @@ define_builtins! {
         25 INT_REM: "rem"
         26 INT_REM_ARG_0: "rem#arg0"
         27 INT_REM_ARG_1: "rem#arg1"
+        28 INT_IS_ODD: "isOdd"
+        29 INT_IS_ODD_ARG: "isOdd#arg"
+        30 INT_IS_EVEN: "isEven"
+        31 INT_IS_EVEN_ARG: "isEven#arg"
     }
     3 FLOAT: "Float" => {
         0 FLOAT_FLOAT: "Float" imported // the Float.Float type alias