diff --git a/link/handlers.go b/link/handlers.go
index aa7c178..912372d 100644
--- a/link/handlers.go
+++ b/link/handlers.go
@@ -53,7 +53,7 @@ func allRetrievalHandler(ctx echo.Context, serv Service) error {
 	limit := 20
 	if v := ctx.QueryParam("limit"); v != "" {
 		num, err := strconv.Atoi(v)
-		if err != nil {
+		if err != nil || num < 0 {
 			return echo.NewHTTPError(http.StatusBadRequest, "Invalid limit value.")
 		}
 
@@ -63,7 +63,7 @@ func allRetrievalHandler(ctx echo.Context, serv Service) error {
 	offset := 0
 	if v := ctx.QueryParam("offset"); v != "" {
 		num, err := strconv.Atoi(v)
-		if err != nil {
+		if err != nil || num < 0 {
 			return echo.NewHTTPError(http.StatusBadRequest, "Invalid offset value.")
 		}