diff --git a/Include/unicodeobject.h b/Include/unicodeobject.h
index 2d0d77e..5b87718 100644
--- a/Include/unicodeobject.h
+++ b/Include/unicodeobject.h
@@ -2309,6 +2309,10 @@
 PyAPI_FUNC(int) _PyUnicode_CheckConsistency(
     PyObject *op,
     int check_content);
+#elif !defined(NDEBUG)
+/* For asserts that call _PyUnicode_CheckConsistency(), which would
+ * otherwise be a problem when building with asserts but without Py_DEBUG. */
+#define _PyUnicode_CheckConsistency(op, check_content) PyUnicode_Check(op)
 #endif
 
 #ifndef Py_LIMITED_API