diff --git a/scheme-gauche/Dockerfile b/scheme-gauche/Dockerfile
index 5130dbf..42d789f 100644
--- a/scheme-gauche/Dockerfile
+++ b/scheme-gauche/Dockerfile
@@ -1 +1 @@
-FROM schemers/gauche:latest
+FROM schemers/gauche:latest@sha256:88e8cb2970f018071a49d16f214bf55f27f219a12ad7f5eaacd68086e6b199fa