diff --git a/seafile_sync/Dockerfile b/seafile_sync/Dockerfile
index 4d256ee..7bfe406 100644
--- a/seafile_sync/Dockerfile
+++ b/seafile_sync/Dockerfile
@@ -12,11 +12,11 @@ FROM flowgunso/seafile-client:latest
 #    && 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