diff --git a/README.md b/README.md
index 2557146..3a0c092 100644
--- a/README.md
+++ b/README.md
@@ -9,6 +9,6 @@ docker run -it \
     -e REMOTE_BRANCH=<branch> \
     -e TARGET_DIR=<path> \
 # Optional
-    -e FLATTENFOLDER=true \
+    -e FLATTEN_FOLDER=true \
 -d djpbessems/git-sidecar
 ```
\ No newline at end of file