diff --git a/lib/diffcrypt/rails/encrypted_configuration.rb b/lib/diffcrypt/rails/encrypted_configuration.rb
index 8b2237d..405531f 100644
--- a/lib/diffcrypt/rails/encrypted_configuration.rb
+++ b/lib/diffcrypt/rails/encrypted_configuration.rb
@@ -73,7 +73,7 @@ def key
       # does not raise MissingKeyError when +raise_if_missing_key+ is true.
       # @return [Boolean]
       def key?
-        read_env_key || read_key_file
+        !!(read_env_key || read_key_file)
       end
 
       def change(&block)