diff --git a/docker/scripts/environment.sh b/docker/scripts/environment.sh
index 60ff8a4..e9812be 100755
--- a/docker/scripts/environment.sh
+++ b/docker/scripts/environment.sh
@@ -4,7 +4,7 @@ DESKTOP_ENVIRONMENT_USER=$USER
 DESKTOP_ENVIRONMENT_CONTAINER_IMAGE=desktop-environment
 DESKTOP_ENVIRONMENT_CONTAINER_NAME=${DESKTOP_ENVIRONMENT_CONTAINER_NAME-$DESKTOP_ENVIRONMENT_CONTAINER_IMAGE}
 DESKTOP_ENVIRONMENT_GITHUB_TOKEN=${DESKTOP_ENVIRONMENT_GITHUB_TOKEN-}
-DESKTOP_ENVIRONMENT_GITHUB_USER=$(git --git-dir $REPO_ROOT/.git remote get-url origin | sed -E  's;.*github.com.(.*)/.*;\1;')
+DESKTOP_ENVIRONMENT_GITHUB_USER=$(git --git-dir $REPO_ROOT/.git remote get-url origin | sed -E 's;.*github.com.(.*)/.*;\1;' | tr A-Z a-z)
 DESKTOP_ENVIRONMENT_REGISTRY=${DESKTOP_ENVIRONMENT_REGISTRY-$DESKTOP_ENVIRONMENT_GITHUB_USER}
 
 # Desktop environment repository information