diff --git a/seafile_sync/Dockerfile b/seafile_sync/Dockerfile
index 2e326e1..b9931e1 100644
--- a/seafile_sync/Dockerfile
+++ b/seafile_sync/Dockerfile
@@ -2,8 +2,8 @@
 FROM flowgunso/seafile-client:latest
 
 ENV \
-    SEAF_SERVER_URL: SERVER_URL \
-    SEAF_USERNAME: USERNAME \
-    SEAF_PASSWORD: PASSWORD \
-    SEAF_LIBRARY_UUID: LIBRARY_UUID
+    SEAF_SERVER_URL="SERVER_URL" \
+    SEAF_USERNAME="USERNAME" \
+    SEAF_PASSWORD="PASSWORD" \
+    SEAF_LIBRARY_UUID="LIBRARY_UUID"