diff --git a/application/source/command.go b/application/source/command.go
index aa2efd03b66bcfa2b2d8112c54e008edaab441fc..405a53fd05552e385aa555de7e2cd1627ab7bc93 100644
--- a/application/source/command.go
+++ b/application/source/command.go
@@ -90,6 +90,12 @@ func (d *Definition) PrepareTemplate(s *xflags.Settings[Definition]) {
 		if info.IsDir() {
 			return nil
 		}
+
+		ext := filepath.Ext(path)
+		if ext != ".html" && ext != ".htm" {
+			return nil
+		}
+
 		return template2.PrepareHtmlFile(path, d.Template.Prepare.Output, storage)
 	})