diff --git a/x b/x
index eb36c31..e1bb9e6 100644
--- a/x
+++ b/x
@@ -12,6 +12,32 @@ GIT_USERNAME=oxidized-selfmade
 GIT_USER_MAIL=michael.grote@posteo.de
 GIT_REPO_REMOTE_NAME=origin
 
+# Checks
+if [ ! -v $GIT_REPO_PATH ]; then
+    echo "GIT_REPO_PATH is not set."
+    exit 3
+fi
+if [ ! -v $GIT_REPO_BRANCH ]; then
+    echo "GIT_REPO_BRANCH is not set."
+    exit 3
+fi
+if [ ! -v $GIT_USERNAME ]; then
+    echo "GIT_USERNAME is not set."
+    exit 3
+fi
+if [ ! -v $GIT_USER_MAIL ]; then
+    echo "GIT_USER_MAIL is not set."
+    exit 3
+fi
+if [ ! -v $GIT_REPO_REMOTE_NAME ]; then
+    echo "GIT_REPO_REMOTE_NAME is not set."
+    exit 3
+fi
+if [ ! -v $DEVICES ]; then
+    echo "DEVICES is not set."
+    exit 3
+fi
+
 git config --global user.email "$GIT_USER_MAIL"
 git config --global user.name "$GIT_USERNAME"