diff --git a/cmd/image-builder/manifest.go b/cmd/image-builder/manifest.go
index 5c46ab3..5e14637 100644
--- a/cmd/image-builder/manifest.go
+++ b/cmd/image-builder/manifest.go
@@ -41,13 +41,13 @@ func sbomWriter(outputDir, filename string, content io.Reader) error {
 	if err != nil {
 		return err
 	}
-	// ensure we do not leak FDs if the function returns prematurely
 	defer f.Close()
 
 	if _, err := io.Copy(f, content); err != nil {
 		return err
 	}
-	return f.Close()
+
+	return f.Sync()
 }
 
 // used in tests