diff --git a/crawler/colly.go b/crawler/colly.go
index 817cc42..3797eb8 100644
--- a/crawler/colly.go
+++ b/crawler/colly.go
@@ -26,6 +26,7 @@ package crawler
 import (
 	"fmt"
 	"net/url"
+	"os"
 	"regexp"
 	"strings"
 	"time"
@@ -50,6 +51,11 @@ func Crawler(target string, txt string, html string, delayTime int, concurrency
 		targetTemp = utils.GetHost(target)
 	}
 
+	if targetTemp == "" {
+		fmt.Println("The URL provided is not built in a proper way: " + target)
+		os.Exit(1)
+	}
+
 	//clean target input
 	target = utils.RemoveProtocol(target)