diff --git a/index.js b/index.js
index 8785ddc..97d85f7 100644
--- a/index.js
+++ b/index.js
@@ -3,7 +3,7 @@
 const statusCodeCacheableByDefault = [200, 203, 204, 206, 300, 301, 404, 405, 410, 414, 501];
 
 // This implementation does not understand partial responses (206)
-const understoodStatuses = [200, 204, 301, 302, 303, 404, 410, 501];
+const understoodStatuses = [200, 203, 204, 300, 301, 302, 303, 307, 308, 404, 405, 410, 414, 501];
 
 const hopByHopHeaders = {'connection':true, 'keep-alive':true, 'proxy-authenticate':true, 'proxy-authorization':true, 'te':true, 'trailers':true, 'transfer-encoding':true, 'upgrade':true};