diff --git a/seafile_sync/Dockerfile b/seafile_sync/Dockerfile
index 4d256ee..1c3fce1 100644
--- a/seafile_sync/Dockerfile
+++ b/seafile_sync/Dockerfile
@@ -10,13 +10,12 @@ FROM flowgunso/seafile-client:latest
 
 #RUN mkdir /library \
 #    && ln -s /config /library
-
 ENV \
-    SEAF_SERVER_URL="SERVER_URL" \
-    SEAF_USERNAME="USERNAME" \
-    SEAF_PASSWORD="PASSWORD" \
-    SEAF_LIBRARY_UUID="LIBRARY_UUID" \
-    SEAF_SKIP_SSL_CERT="SKIP_SSL_CERT"
+    SEAF_SERVER_URL="${SERVER_URL}" \
+    SEAF_USERNAME="${USERNAME}" \
+    SEAF_PASSWORD="${PASSWORD}" \
+    SEAF_LIBRARY_UUID="${LIBRARY_UUID}" \
+    SEAF_SKIP_SSL_CERT="${SKIP_SSL_CERT}"
 
 #RUN mkdir /config
 #RUN mkdir /library