diff --git a/Dockerfile b/Dockerfile
index 432be62..4722ec6 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -153,8 +153,7 @@ RUN \
     kill_installer() { \
         pkill -9 "$installerName" > /dev/null 2>&1; \
     }; \
-    display=:90; \
-    export DISPLAY="$display"; \
+    export DISPLAY=:90; \
     mkdir -p --mode=777 /tmp/.X11-unix; \
     # Create job for waiting for Xvfb to start
     watchStarting="$(mktemp)"; \