diff --git a/newlib/libc/include/sys/reent.h b/newlib/libc/include/sys/reent.h
index e1ed8b421..8b67889ac 100644
--- a/newlib/libc/include/sys/reent.h
+++ b/newlib/libc/include/sys/reent.h
@@ -454,8 +454,8 @@ extern const struct __sFILE_fake __sf_fake_stderr;
     (var)->_stderr = (__FILE *)&__sf_fake_stderr; \
   }
 
-/* Only built the assert() calls if we are built with debugging.  */
-#if DEBUG
+/* Only add assert() calls if we are specified to debug.  */
+#ifdef _REENT_CHECK_DEBUG
 #include <assert.h>
 #define __reent_assert(x) assert(x)
 #else