diff --git a/lib/googleauth/user_refresh.rb b/lib/googleauth/user_refresh.rb
index ebb2e24..65e99d0 100644
--- a/lib/googleauth/user_refresh.rb
+++ b/lib/googleauth/user_refresh.rb
@@ -67,9 +67,9 @@ module Google
         json_key_io, scope = options.values_at(:json_key_io, :scope)
         user_creds = self.class.read_json_key(json_key_io) if json_key_io
         user_creds ||= {
-          client_id: ENV[CredentialsLoader::CLIENT_ID_VAR],
-          client_secret: ENV[CredentialsLoader::CLIENT_SECRET_VAR],
-          refresh_token: ENV[CredentialsLoader::REFRESH_TOKEN_VAR]
+          'client_id'     => ENV[CredentialsLoader::CLIENT_ID_VAR],
+          'client_secret' => ENV[CredentialsLoader::CLIENT_SECRET_VAR],
+          'refresh_token' => ENV[CredentialsLoader::REFRESH_TOKEN_VAR]
         }
 
         super(token_credential_uri: TOKEN_CRED_URI,
diff --git a/spec/googleauth/user_refresh_spec.rb b/spec/googleauth/user_refresh_spec.rb
index 64047ec..dab9f74 100644
--- a/spec/googleauth/user_refresh_spec.rb
+++ b/spec/googleauth/user_refresh_spec.rb
@@ -142,6 +142,9 @@ describe Google::Auth::UserRefreshCredentials do
       ENV[REFRESH_TOKEN_VAR] = cred_json[:refresh_token]
       ENV[ACCOUNT_TYPE_VAR] = cred_json[:type]
       expect(@clz.from_env(@scope)).to_not be_nil
+      expect(subject.client_id).to eq(cred_json[:client_id])
+      expect(subject.client_secret).to eq(cred_json[:client_secret])
+      expect(subject.refresh_token).to eq(cred_json[:refresh_token])
     end
   end