diff --git a/packages/core/pattern.mjs b/packages/core/pattern.mjs
index 41b09ea20..beefc5971 100644
--- a/packages/core/pattern.mjs
+++ b/packages/core/pattern.mjs
@@ -2720,7 +2720,7 @@ export function stepcat(...timepats) {
   if (timepats.length === 0) {
     return nothing;
   }
-  const findsteps = (x) => (Array.isArray(x) ? x : [x._steps, x]);
+  const findsteps = (x) => (Array.isArray(x) ? x : [x._steps ?? 1, x]);
   timepats = timepats.map(findsteps);
   if (timepats.find((x) => x[0] === undefined)) {
     const times = timepats.map((a) => a[0]).filter((x) => x !== undefined);
diff --git a/packages/core/test/pattern.test.mjs b/packages/core/test/pattern.test.mjs
index 45a1e2a98..07bdcdda7 100644
--- a/packages/core/test/pattern.test.mjs
+++ b/packages/core/test/pattern.test.mjs
@@ -52,6 +52,7 @@ import {
   stackCentre,
   stepcat,
   sometimes,
+  expand,
 } from '../index.mjs';
 
 import { steady } from '../signal.mjs';
@@ -1179,6 +1180,9 @@ describe('Pattern', () => {
     it('calculates undefined steps as the average', () => {
       expect(sameFirst(stepcat(pure(1), pure(2), pure(3).setSteps(undefined)), fastcat(1, 2, 3)));
     });
+    it('works with auto-reified values', () => {
+      expect(sameFirst(stepcat(expand(3, 'bd'), 'rim'), stepcat(expand(3, 'bd'), pure('rim'))));
+    });
   });
   describe('shrink', () => {
     it('can shrink', () => {