diff --git a/openapi3filter/middleware_test.go b/openapi3filter/middleware_test.go
index 4d88aaf91..930af2ada 100644
--- a/openapi3filter/middleware_test.go
+++ b/openapi3filter/middleware_test.go
@@ -420,7 +420,7 @@ paths:
 	// requests.
 	squareHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		xParam := path.Base(r.URL.Path)
-		x, err := strconv.Atoi(xParam)
+		x, err := strconv.ParseInt(xParam, 10, 64)
 		if err != nil {
 			panic(err)
 		}