diff --git a/eng/native/build-commons.sh b/eng/native/build-commons.sh
index 404a27e612ecc3..c0631ecda1308e 100755
--- a/eng/native/build-commons.sh
+++ b/eng/native/build-commons.sh
@@ -300,7 +300,7 @@ __TargetRid=''
 
 # Get the number of processors available to the scheduler
 platform="$(uname -s | tr '[:upper:]' '[:lower:]')"
-if [[ "$platform" == "freebsd" ]]; then
+if [[ "$platform" == "freebsd" || "$platform" == "openbsd" ]]; then
   __NumProc="$(($(sysctl -n hw.ncpu)+1))"
 elif [[ "$platform" == "netbsd" || "$platform" == "sunos" ]]; then
   __NumProc="$(($(getconf NPROCESSORS_ONLN)+1))"