diff --git a/crypto/fscrypt/KeyStorage.h b/crypto/fscrypt/KeyStorage.h
index b88cdc6..2c88820 100755
--- a/crypto/fscrypt/KeyStorage.h
+++ b/crypto/fscrypt/KeyStorage.h
@@ -60,7 +60,7 @@
 
 // Retrieve the key from the named directory.
 bool retrieveKey(const std::string& dir, const KeyAuthentication& auth, KeyBuffer* key,
-                 bool keepOld = false);
+                 bool keepOld);
 
 // Securely destroy the key stored in the named directory and delete the directory.
 bool destroyKey(const std::string& dir);