diff --git a/Makefile b/Makefile
index 1876c51..e7a68ec 100644
--- a/Makefile
+++ b/Makefile
@@ -35,22 +35,18 @@ INSPIRCD_SELECTORS := \
 	and not strict \
 	$(EXTRA_SELECTORS)
 
-# HelpTestCase fails because it returns NOTICEs instead of numerics
 IRCU2_SELECTORS := \
 	not Ergo \
 	and not deprecated \
 	and not strict \
 	$(EXTRA_SELECTORS)
 
-# same justification as ircu2
-# lusers "unregistered" tests fail because 
 NEFARIOUS_SELECTORS := \
 	not Ergo \
 	and not deprecated \
 	and not strict \
 	$(EXTRA_SELECTORS)
 
-# same justification as ircu2
 SNIRCD_SELECTORS := \
 	not Ergo \
 	and not deprecated \
diff --git a/irctest/cases.py b/irctest/cases.py
index eea0f8c..30b1aed 100644
--- a/irctest/cases.py
+++ b/irctest/cases.py
@@ -802,7 +802,7 @@ def xfailIf(
     def decorator(f: Callable[..., _TReturn]) -> Callable[..., _TReturn]:
         @functools.wraps(f)
         def newf(self: _TSelf, *args: Any, **kwargs: Any) -> _TReturn:
-            if condition(self):
+            if condition(self, *args, **kwargs):
                 try:
                     return f(self, *args, **kwargs)
                 except Exception:
@@ -819,7 +819,10 @@ def xfailIf(
 def xfailIfSoftware(
     names: List[str], reason: str
 ) -> Callable[[Callable[..., _TReturn]], Callable[..., _TReturn]]:
-    return xfailIf(lambda testcase: testcase.controller.software_name in names, reason)
+    def pred(testcase: _IrcTestCase, *args: Any, **kwargs: Any) -> bool:
+        return testcase.controller.software_name in names
+
+    return xfailIf(pred, reason)
 
 
 def mark_services(cls: TClass) -> TClass:
diff --git a/irctest/server_tests/who.py b/irctest/server_tests/who.py
index 15bdeb3..0e4b280 100644
--- a/irctest/server_tests/who.py
+++ b/irctest/server_tests/who.py
@@ -496,6 +496,46 @@ class WhoTestCase(BaseWhoTestCase, cases.BaseServerTestCase):
             params=["otherNick", InsensitiveStr("coolNick"), ANYSTR],
         )
 
+    @pytest.mark.parametrize("char", "cuihsnfdlaor")
+    @cases.xfailIf(
+        lambda self, char: bool(
+            char == "l" and self.controller.software_name == "ircu2"
+        ),
+        "https://github.com/UndernetIRC/ircu2/commit/17c539103abbd0055b2297e17854cd0756c85d62",
+    )
+    @cases.xfailIf(
+        lambda self, char: bool(
+            char == "l" and self.controller.software_name == "Nefarious"
+        ),
+        "https://github.com/evilnet/nefarious2/pull/73",
+    )
+    def testWhoxOneChar(self, char):
+        self._init()
+        if "WHOX" not in self.server_support:
+            raise runner.IsupportTokenNotSupported("WHOX")
+
+        self.sendLine(2, f"WHO coolNick %{char}")
+        messages = self.getMessages(2)
+
+        self.assertEqual(len(messages), 2, "Unexpected number of messages")
+
+        (reply, end) = messages
+
+        self.assertMessageMatch(
+            reply,
+            command=RPL_WHOSPCRPL,
+            params=[
+                "otherNick",
+                StrRe(".+"),
+            ],
+        )
+
+        self.assertMessageMatch(
+            end,
+            command=RPL_ENDOFWHO,
+            params=["otherNick", InsensitiveStr("coolNick"), ANYSTR],
+        )
+
     def testWhoxToken(self):
         """https://github.com/ircv3/ircv3-specifications/pull/482"""
         self._init()