diff --git a/compiler/gen/src/llvm/build.rs b/compiler/gen/src/llvm/build.rs
index bf8b9a7261..3b99235197 100644
--- a/compiler/gen/src/llvm/build.rs
+++ b/compiler/gen/src/llvm/build.rs
@@ -1102,13 +1102,7 @@ fn call_with_args<'a, 'ctx, 'env>(
 
             // Bounds check: only proceed if index < length.
             // Otherwise, return the list unaltered.
-            //
-            // Note: Check for index < length as the "true" condition,
-            // to avoid misprediction. (In practice this should usually pass,
-            // and CPUs generally default to predicting that a forward jump
-            // shouldn't be taken; that is, they predict "else" won't be taken.)
-            let comparison =
-                builder.build_int_compare(IntPredicate::ULT, elem_index, list_len, "bounds_check");
+            let comparison = bounds_check_comparison(builder, elem_index, list_len);
 
             // If the index is in bounds, clone and mutate in place.
             let then_val: BasicValueEnum = {
@@ -1272,3 +1266,16 @@ fn clone_list<'a, 'ctx, 'env>(
 
     (struct_val.into_struct_value(), ptr_val)
 }
+
+fn bounds_check_comparison<'ctx>(
+    builder: &Builder<'ctx>,
+    elem_index: IntValue<'ctx>,
+    len: IntValue<'ctx>,
+) -> IntValue<'ctx> {
+    //
+    // Note: Check for index < length as the "true" condition,
+    // to avoid misprediction. (In practice this should usually pass,
+    // and CPUs generally default to predicting that a forward jump
+    // shouldn't be taken; that is, they predict "else" won't be taken.)
+    builder.build_int_compare(IntPredicate::ULT, elem_index, len, "bounds_check")
+}