diff --git a/mechanicalsoup/browser.py b/mechanicalsoup/browser.py
index bcb3e25f..0e2f94cf 100644
--- a/mechanicalsoup/browser.py
+++ b/mechanicalsoup/browser.py
@@ -163,7 +163,10 @@ def _request(self, form, url=None, **kwargs):
             name = tag.get("name")  # name-attribute of tag
 
             if tag.name == "input":
-                if tag.get("type") in ("radio", "checkbox"):
+                if (
+                        tag.get("type") is not None and
+                        tag.get("type").lower() in ("radio", "checkbox")
+                ):
                     if "checked" not in tag.attrs:
                         continue
                     value = tag.get("value", "on")
diff --git a/tests/test_browser.py b/tests/test_browser.py
index 52d408dd..3bc3b300 100644
--- a/tests/test_browser.py
+++ b/tests/test_browser.py
@@ -45,14 +45,14 @@ def test__request(httpbin):
       <textarea name="comments">freezer</textarea>
       <fieldset>
         <legend> Pizza Size </legend>
-        <p><input type=radio name=size value="small">Small</p>
-        <p><input type=radio name=size value="medium" checked>Medium</p>
+        <p><input type=RADIO name=size value="small">Small</p>
+        <p><input type=radiO name=size value="medium" checked>Medium</p>
         <p><input type=radio name=size value="large">Large</p>
       </fieldset>
       <fieldset>
         <legend> Pizza Toppings </legend>
-        <p><input type=checkbox name="topping" value="bacon" checked>Bacon</p>
-        <p><input type=checkbox name="topping" value="cheese">Extra Cheese</p>
+        <p><input type=CHECKBOX name="topping" value="bacon" checked>Bacon</p>
+        <p><input type=checkBox name="topping" value="cheese">Extra Cheese</p>
         <p><input type=checkbox name="topping" value="onion" checked>Onion</p>
         <p><input type=checkbox name="topping" value="mushroom">Mushroom</p>
       </fieldset>