diff --git a/lib/core/settings.py b/lib/core/settings.py
index 5fd808758..539eba042 100644
--- a/lib/core/settings.py
+++ b/lib/core/settings.py
@@ -18,7 +18,7 @@ from lib.core.enums import OS
 from thirdparty.six import unichr as _unichr
 
 # sqlmap version (<major>.<minor>.<month>.<monthly commit>)
-VERSION = "1.3.11.51"
+VERSION = "1.3.11.52"
 TYPE = "dev" if VERSION.count('.') > 2 and VERSION.split('.')[-1] != '0' else "stable"
 TYPE_COLORS = {"dev": 33, "stable": 90, "pip": 34}
 VERSION_STRING = "sqlmap/%s#%s" % ('.'.join(VERSION.split('.')[:-1]) if VERSION.count('.') > 2 and VERSION.split('.')[-1] == '0' else VERSION, TYPE)
diff --git a/lib/utils/crawler.py b/lib/utils/crawler.py
index 883847480..0730a05bb 100644
--- a/lib/utils/crawler.py
+++ b/lib/utils/crawler.py
@@ -43,6 +43,9 @@ from thirdparty.six.moves import http_client as _http_client
 from thirdparty.six.moves import urllib as _urllib
 
 def crawl(target):
+    if not target:
+        return
+
     try:
         visited = set()
         threadData = getCurrentThreadData()