diff --git a/keystore/user_state.h b/keystore/user_state.h
index 6cac02a..a1dc6a2 100644
--- a/keystore/user_state.h
+++ b/keystore/user_state.h
@@ -74,7 +74,10 @@
     bool operator<(uid_t userId) const;
 
   private:
-    static const int MASTER_KEY_SIZE_BYTES = 16;
+    static const int SHA1_DIGEST_SIZE_BYTES = 16;
+    static const int SHA256_DIGEST_SIZE_BYTES = 32;
+
+    static const int MASTER_KEY_SIZE_BYTES = SHA1_DIGEST_SIZE_BYTES;
     static const int MASTER_KEY_SIZE_BITS = MASTER_KEY_SIZE_BYTES * 8;
 
     static const int MAX_RETRY = 4;