diff --git a/crates/compiler/gen_dev/src/lib.rs b/crates/compiler/gen_dev/src/lib.rs
index ddec2b4ea7..65996e763f 100644
--- a/crates/compiler/gen_dev/src/lib.rs
+++ b/crates/compiler/gen_dev/src/lib.rs
@@ -578,6 +578,8 @@ trait Backend<'a> {
                 );
                 self.build_num_div(sym, &args[0], &args[1], ret_layout)
             }
+
+            LowLevel::NumRemUnchecked => self.build_num_rem(sym, &args[0], &args[1], ret_layout),
             LowLevel::NumNeg => {
                 debug_assert_eq!(
                     1,
@@ -1307,6 +1309,9 @@ trait Backend<'a> {
     /// build_num_mul stores `src1 / src2` into dst.
     fn build_num_div(&mut self, dst: &Symbol, src1: &Symbol, src2: &Symbol, layout: &InLayout<'a>);
 
+    /// build_num_mul stores `src1 % src2` into dst.
+    fn build_num_rem(&mut self, dst: &Symbol, src1: &Symbol, src2: &Symbol, layout: &InLayout<'a>);
+
     /// build_num_neg stores the negated value of src into dst.
     fn build_num_neg(&mut self, dst: &Symbol, src: &Symbol, layout: &InLayout<'a>);