diff --git a/cmake/config-ix.cmake b/cmake/config-ix.cmake
index 17feffe56ea..320aaf89940 100755
--- a/cmake/config-ix.cmake
+++ b/cmake/config-ix.cmake
@@ -86,6 +86,7 @@ check_symbol_exists(mkdtemp unistd.h HAVE_MKDTEMP)
 check_symbol_exists(mkstemp unistd.h HAVE_MKSTEMP)
 check_symbol_exists(mktemp unistd.h HAVE_MKTEMP)
 check_symbol_exists(pthread_mutex_lock pthread.h HAVE_PTHREAD_MUTEX_LOCK)
+check_symbol_exists(sbrk unistd.h HAVE_SBRK)
 check_symbol_exists(strtoll stdlib.h HAVE_STRTOLL)
 check_symbol_exists(strerror string.h HAVE_STRERROR)
 check_symbol_exists(strerror_r string.h HAVE_STRERROR_R)