diff --git a/src/microhttpd/digestauth.c b/src/microhttpd/digestauth.c
index 6033c166..649fef62 100644
--- a/src/microhttpd/digestauth.c
+++ b/src/microhttpd/digestauth.c
@@ -63,7 +63,7 @@
 /**
  * Macro to avoid using VLAs if the compiler does not support them.
  */
-#if __STDC_NO_VLA__
+#ifndef HAVE_C_VARARRAYS
 /**
  * Return #MAX_DIGEST.
  *