diff --git a/docker-entrypoint.sh b/docker-entrypoint.sh
index 2a33acb..4c26f15 100644
--- a/docker-entrypoint.sh
+++ b/docker-entrypoint.sh
@@ -1,17 +1,17 @@
 #!/usr/bin/env bash
 
-if [ "${GCE_SSH_KEY}" ]; then
-    echo "${GCE_SSH_KEY}" > $HOME/.ssh/google_compute_engine
+if [ "$GCE_SSH_KEY" ]; then
+    echo "$GCE_SSH_KEY" > $HOME/.ssh/google_compute_engine
     chmod 600 $HOME/.ssh/google_compute_engine
 fi
 
-if [ "${GCE_CREDENTIALS_JSON}" ] && [ "${GCE_CREDENTIALS_FILE}" ]; then
-    DIR=$(dirname "${GCE_CREDENTIALS_FILE}")
+if [ "$GCE_CREDENTIALS_JSON" ] && [ "$GCE_CREDENTIALS_FILE" ]; then
+    DIR=$(dirname "$GCE_CREDENTIALS_FILE")
     mkdir -p "${DIR}"
-    echo "${GCE_CREDENTIALS_JSON}" > "${GCE_CREDENTIALS_FILE}"
+    echo "$GCE_CREDENTIALS_JSON" > "$GCE_CREDENTIALS_FILE"
 fi
 
 if [ "${MOLECULE_CUSTOM_MODULES_REPO}" ]; then
     mkdir ./library/
-    git clone "${MOLECULE_CUSTOM_MODULES_REPO}" ./library/
+    git clone "$MOLECULE_CUSTOM_MODULES_REPO" ./library/
 fi