diff --git a/scripts/setup-centos9.sh b/scripts/setup-centos9.sh
index 04224adc90d1..1cf43630c4f1 100755
--- a/scripts/setup-centos9.sh
+++ b/scripts/setup-centos9.sh
@@ -102,7 +102,7 @@ function install_lzo {
   (
     cd ${DEPENDENCY_DIR}/lzo
     ./configure --prefix=${INSTALL_PREFIX} --enable-shared --disable-static --docdir=/usr/share/doc/lzo-2.10
-    make "-j$(nproc)"
+    make "-j${NPROC}"
     make install
   )
 }
@@ -117,10 +117,10 @@ function install_boost {
       # clang of version 15 when toolset clang-15 is used.
       # This reconciles the project-config.jam generation with what the b2 build system allows for customization.
       sed -i 's/using clang-15/using clang : 15/g' project-config.jam
-      ${SUDO} ./b2 "-j$(nproc)" -d0 install threading=multi toolset=clang-15 --without-python
+      ${SUDO} ./b2 "-j${NPROC}" -d0 install threading=multi toolset=clang-15 --without-python
     else
       ./bootstrap.sh --prefix=${INSTALL_PREFIX}
-      ${SUDO} ./b2 "-j$(nproc)" -d0 install threading=multi --without-python
+      ${SUDO} ./b2 "-j${NPROC}" -d0 install threading=multi --without-python
     fi
   )
 }
diff --git a/scripts/setup-ubuntu.sh b/scripts/setup-ubuntu.sh
index 5874e98e9651..482e7ea3241d 100755
--- a/scripts/setup-ubuntu.sh
+++ b/scripts/setup-ubuntu.sh
@@ -128,10 +128,10 @@ function install_boost {
       # clang of version 15 when toolset clang-15 is used.
       # This reconciles the project-config.jam generation with what the b2 build system allows for customization.
       sed -i 's/using clang-15/using clang : 15/g' project-config.jam
-      ${SUDO} ./b2 "-j$(nproc)" -d0 install threading=multi toolset=clang-15 --without-python
+      ${SUDO} ./b2 "-j${NPROC}" -d0 install threading=multi toolset=clang-15 --without-python
     else
       ./bootstrap.sh --prefix=${INSTALL_PREFIX}
-      ${SUDO} ./b2 "-j$(nproc)" -d0 install threading=multi --without-python
+      ${SUDO} ./b2 "-j${NPROC}" -d0 install threading=multi --without-python
     fi
   )
 }