don't confuse autocert

database/storage.go

@@ -1,6 +1,7 @@
 package database
 
 import (
+	"github.com/asdine/storm"
 	"golang.org/x/crypto/acme/autocert"
 	"golang.org/x/net/context"
 )
@@ -34,7 +35,16 @@ type storageManager struct {
 }
 
 func (s *storageManager) Get(ctx context.Context, key string) ([]byte, error) {
-	return s.GetCert(ctx, key)
+	data, err := s.GetCert(ctx, key)
+	if err != nil {
+		if err == storm.ErrNotFound {
+			return nil, autocert.ErrCacheMiss
+		} else {
+			return nil, err
+		}
+	}
+
+	return data, nil
 }
 
 func (s *storageManager) Put(ctx context.Context, key string, data []byte) error {