diff --git a/httpr.go b/httpr.go
index ad79a10..700bb99 100644
--- a/httpr.go
+++ b/httpr.go
@@ -38,14 +38,13 @@ func newPath(path string) (path, error) {
 
 // newServePath is a reduced version of newPath for ServeHTTP.
 func newServePath(path string) (path, error) {
-	pathLen := len(path)
-
 	if path[0] != '/' {
 		return nil, errors.New("path should start with a slash symbol \"/\"")
 	}
 
 	path = strings.ReplaceAll(path, "//", "/")
 
+	pathLen := len(path)
 	if path[pathLen-1] == '/' {
 		path = path[:pathLen-1]
 	}