diff --git a/acconfig.h b/acconfig.h
index 5b59f2e9f8..8d667442bc 100644
--- a/acconfig.h
+++ b/acconfig.h
@@ -17,12 +17,6 @@
  ***/
 @TOP@
 
-/**
- * define if pthread_setconcurrency() should be called to tell the
- * OS how many threads we might want to run.
- */
-#undef CALL_PTHREAD_SETCONCURRENCY
-
 /** define if flockfile() is available */
 #undef HAVE_FLOCKFILE
 
diff --git a/config.h.in b/config.h.in
index 546c17727e..e838e776a4 100644
--- a/config.h.in
+++ b/config.h.in
@@ -17,12 +17,6 @@
  *** it does not get installed.
  ***/
 
-/**
- * define if pthread_setconcurrency() should be called to tell the
- * OS how many threads we might want to run.
- */
-#undef CALL_PTHREAD_SETCONCURRENCY
-
 /** define if flockfile() is available */
 #undef HAVE_FLOCKFILE
 
diff --git a/lib/isc/pthreads/thread.c b/lib/isc/pthreads/thread.c
index c84196799b..5f82475ed5 100644
--- a/lib/isc/pthreads/thread.c
+++ b/lib/isc/pthreads/thread.c
@@ -68,11 +68,7 @@ isc_thread_create(isc_threadfunc_t func, isc_threadarg_t arg,
 
 void
 isc_thread_setconcurrency(unsigned int level) {
-#if defined(CALL_PTHREAD_SETCONCURRENCY)
 	(void)pthread_setconcurrency(level);
-#else
-	UNUSED(level);
-#endif
 }
 
 void