diff --git a/airflow/Dockerfile b/airflow/Dockerfile
index 84b58f9d7..4789f37ad 100644
--- a/airflow/Dockerfile
+++ b/airflow/Dockerfile
@@ -2,7 +2,7 @@ FROM quay.io/astronomer/astro-runtime:11.8.0
 
 ENV DATA_DIR=data_tiles
 
-RUN mkdir -p $DATA_DIR
+RUN mkdir -p "$DATA_DIR"
 
 # Install tippecanoe
 RUN git clone https://github.com/mapbox/tippecanoe.git /home/astro/tippecanoe