diff --git a/cmake/build_moose-core.sh.in b/cmake/build_moose-core.sh.in
index 0cf1778e0c0807a2236067036e3ece7cc9ba04f8..820010c21d3ec4f92742dcd55e02777cdc078927 100755
--- a/cmake/build_moose-core.sh.in
+++ b/cmake/build_moose-core.sh.in
@@ -6,9 +6,8 @@ set -e
 # NOTICE: This file is parsed by cmake to create a shell script. Not all syntax
 # will play well with cmake. CMAKE replaces @FOO@ and ${FOO} with cmake variable
 # values.
-NPROC=$(nproc)
 if [ -z $MAKEOPTS ]; then
-    export MAKEOPTS="-j${NPROC}"
+    export MAKEOPTS="-j`nproc`"
 fi
 
 echo "Building pymoose and creating bdist."