diff --git a/create_node_env.sh b/create_node_env.sh
index 0df2c890..42afec15 100755
--- a/create_node_env.sh
+++ b/create_node_env.sh
@@ -18,7 +18,7 @@ PATH_ADDITIONS="`pwd`/node_modules/bin:`pwd`/node_modules/.bin"
 
 
 # Verify NPM exists.
-if [ -z "${NPM}" -o ! -x "${NPM}" ]; then
+if [ -z "${NPM}" ] || [ ! -x "${NPM}" ]; then
     echo "Error: ${NPM} isn't executable or doesn't exist."
     exit 1
 fi
diff --git a/create_python_env.sh b/create_python_env.sh
index dca3732c..d35c58d6 100755
--- a/create_python_env.sh
+++ b/create_python_env.sh
@@ -33,7 +33,7 @@ fi
 ${CHOSEN} -m venv "${VENVDIR}"
 
 # Activate the virtual environment, if needed
-if [ -z "${VIRTUAL_ENV}" -o "${VIRTUAL_ENV}" != "${VENVDIR}" ]; then
+if [ -z "${VIRTUAL_ENV}" ] || [ "${VIRTUAL_ENV}" != "${VENVDIR}" ]; then
     source "${VENVDIR}/activate"
 fi