diff --git a/acconfig.h b/acconfig.h
index 369986e9c8..8b4a7ea626 100644
--- a/acconfig.h
+++ b/acconfig.h
@@ -17,12 +17,6 @@
  ***/
 @TOP@
 
-/** define if pthread_attr_getstacksize() is available */
-#undef HAVE_PTHREAD_ATTR_GETSTACKSIZE
-
-/** define if pthread_attr_setstacksize() is available */
-#undef HAVE_PTHREAD_ATTR_SETSTACKSIZE
-
 /** define if you have strerror in the C library. */
 #undef HAVE_STRERROR
 
diff --git a/config.h.in b/config.h.in
index e0e624ad67..619a3b4b37 100644
--- a/config.h.in
+++ b/config.h.in
@@ -17,12 +17,6 @@
  *** it does not get installed.
  ***/
 
-/** define if pthread_attr_getstacksize() is available */
-#undef HAVE_PTHREAD_ATTR_GETSTACKSIZE
-
-/** define if pthread_attr_setstacksize() is available */
-#undef HAVE_PTHREAD_ATTR_SETSTACKSIZE
-
 /** define if you have strerror in the C library. */
 #undef HAVE_STRERROR