diff --git a/callattendant/screening/nomorobo.py b/callattendant/screening/nomorobo.py
index f961b30..6844cb0 100644
--- a/callattendant/screening/nomorobo.py
+++ b/callattendant/screening/nomorobo.py
@@ -37,7 +37,7 @@ def lookup_number(self, number):
         headers = {}
         allowed_codes = [404]  # allow not found response
         content = self.http_get(url, headers, allowed_codes)
-        soup = BeautifulSoup(content, "lxml")  # lxml HTML parser: fast
+        soup = BeautifulSoup(content, "html.parser")
 
         score = 0  # = no spam
 
diff --git a/requirements.txt b/requirements.txt
index 79d6f67..57566cf 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -10,7 +10,6 @@ gpiozero==1.5.1
 iso8601==0.1.12
 itsdangerous==1.1.0
 Jinja2==2.11.2
-lxml==4.5.2
 MarkupSafe==1.1.1
 pigpio==1.46
 pygments