1 files changed, 3 insertions, 0 deletions
diff --git a/build/make/configure.sh b/build/make/configure.sh
index 3324be36e..28a0247d8 100755
--- a/build/make/configure.sh
+++ b/build/make/configure.sh
@@ -980,6 +980,9 @@ EOF
         esac
     fi
 
+    # for sysconf(3) and friends.
+    check_header unistd.h
+
     # glibc needs these
     if enabled linux; then
         add_cflags -D_LARGEFILE_SOURCE