diff --git a/docs/scripts/sphinx-make.sh b/docs/scripts/sphinx-make.sh
index 36596f2..61356bb 100755
--- a/docs/scripts/sphinx-make.sh
+++ b/docs/scripts/sphinx-make.sh
@@ -1,20 +1,34 @@
-#!/bin/bash
+#!/bin/bash -ex
+
+# Not refactored to root Makefile because CI calls this from
+# makefile in /docs (as if 'make -C docs').
+if [ -z "$PYTHON" ]
+then
+PYTHON_INTERP=python3
+else
+PYTHON_INTERP=$(PYTHON)
+fi
+
+# Get the OS
+OS_ID=$(grep '^ID=' /etc/os-release  | cut -f2- -d= | sed -e 's/\"//g')
 
 if [ "$1" == "venv" ]
 then
-    OS_ID=$(grep '^ID=' /etc/os-release  | cut -f2- -d= | sed -e 's/\"//g')
+    # We need to install the venv package on new systems
     if [ "$OS_ID" == "ubuntu" ]
     then
-	sudo apt-get install -y python3-pip
+	sudo apt-get install $CONFIRM python3-venv
     fi
     if [ "$OS_ID" == "centos" ]
     then
-	sudo yum install -y python3-pip
+	sudo yum install $CONFIRM python3-venv
     fi
-    pip3 install --user virtualenv
-    python3 -m virtualenv $VENV_DIR
+
+    # Install the virtual environment
+    $PYTHON_INTERP -m venv $VENV_DIR
     source $VENV_DIR/bin/activate;
-    pip3 install -r $DOCS_DIR/etc/requirements.txt
+    $PYTHON_INTERP -m pip install wheel==0.34.2
+    $PYTHON_INTERP -m pip install -r $DOCS_DIR/etc/requirements.txt
 else
     source $VENV_DIR/bin/activate;
     VERSION=`source $WS_ROOT/src/scripts/version`