diff --git a/cmd/upgrade.go b/cmd/upgrade.go
index 5505f8ac..1335a509 100644
--- a/cmd/upgrade.go
+++ b/cmd/upgrade.go
@@ -144,10 +144,15 @@ func ExtractManifest(origin string) (extensions.Extension, error) {
 		if err != nil {
 			return extensions.Extension{}, err
 		}
+		defer f.Close()
 
 		if _, err := io.Copy(f, resp.Body); err != nil {
 			return extensions.Extension{}, err
 		}
+
+		if err := f.Close(); err != nil {
+			return extensions.Extension{}, err
+		}
 	} else {
 		extensionType = extensions.ExtensionTypeLocal
 		entrypoint = origin