diff --git a/irctest/irc_utils/ambiguities.py b/irctest/irc_utils/ambiguities.py
deleted file mode 100644
index 4fac710..0000000
--- a/irctest/irc_utils/ambiguities.py
+++ /dev/null
@@ -1,23 +0,0 @@
-"""
-Handles ambiguities of RFCs.
-"""
-
-from typing import List
-
-
-def normalize_namreply_params(params: List[str]) -> List[str]:
-    # So… RFC 2812 says:
-    #       "( "=" / "*" / "@" ) <channel>
-    #       :[ "@" / "+" ] <nick> *( " " [ "@" / "+" ] <nick> )
-    # but spaces seem to be missing (eg. before the colon), so we
-    # don't know if there should be one before the <channel> and its
-    # prefix.
-    # So let's normalize this to “with space”, and strip spaces at the
-    # end of the nick list.
-    params = list(params)  # copy the list
-    if len(params) == 3:
-        assert params[1][0] in "=*@", params
-        params.insert(1, params[1][0])
-        params[2] = params[2][1:]
-    params[3] = params[3].rstrip()
-    return params
diff --git a/irctest/server_tests/join.py b/irctest/server_tests/join.py
index 833f9c1..1a78763 100644
--- a/irctest/server_tests/join.py
+++ b/irctest/server_tests/join.py
@@ -6,7 +6,6 @@ The JOIN command  (`RFC 1459
 """
 
 from irctest import cases, runner
-from irctest.irc_utils import ambiguities
 from irctest.numerics import (
     ERR_BADCHANMASK,
     ERR_FORBIDDENCHANNEL,
@@ -75,33 +74,23 @@ class JoinTestCase(cases.BaseServerTestCase):
 
         for m in self.getMessages(1):
             if m.command == "353":
-                self.assertIn(
-                    len(m.params),
-                    (3, 4),
-                    m,
-                    fail_msg="RPL_NAM_REPLY with number of arguments "
-                    "<3 or >4: {msg}",
+                self.assertMessageMatch(
+                    m, params=["foo", StrRe(r"[=\*@]"), "#chan", StrRe("[@+]?foo")]
                 )
-                params = ambiguities.normalize_namreply_params(m.params)
-                self.assertIn(
-                    params[1],
-                    "=*@",
+
+        self.connectClient("bar")
+        self.sendLine(2, "JOIN #chan")
+
+        for m in self.getMessages(2):
+            if m.command == "353":
+                self.assertMessageMatch(
                     m,
-                    fail_msg="Bad channel prefix: {item} not in {list}: {msg}",
-                )
-                self.assertEqual(
-                    params[2],
-                    "#chan",
-                    m,
-                    fail_msg="Bad channel name: {got} instead of " "{expects}: {msg}",
-                )
-                self.assertIn(
-                    params[3],
-                    {"foo", "@foo", "+foo"},
-                    m,
-                    fail_msg="Bad user list: should contain only user "
-                    '"foo" with an optional "+" or "@" prefix, but got: '
-                    "{msg}",
+                    params=[
+                        "bar",
+                        StrRe(r"[=\*@]"),
+                        "#chan",
+                        StrRe("([@+]?foo bar|bar [@+]?foo)"),
+                    ],
                 )
 
     def testJoinTwice(self):
@@ -115,34 +104,8 @@ class JoinTestCase(cases.BaseServerTestCase):
         # if the join is successful, or has an error among the given set.
         for m in self.getMessages(1):
             if m.command == "353":
-                self.assertIn(
-                    len(m.params),
-                    (3, 4),
-                    m,
-                    fail_msg="RPL_NAM_REPLY with number of arguments "
-                    "<3 or >4: {msg}",
-                )
-                params = ambiguities.normalize_namreply_params(m.params)
-                self.assertIn(
-                    params[1],
-                    "=*@",
-                    m,
-                    fail_msg="Bad channel prefix: {item} not in {list}: {msg}",
-                )
-                self.assertEqual(
-                    params[2],
-                    "#chan",
-                    m,
-                    fail_msg="Bad channel name: {got} instead of " "{expects}: {msg}",
-                )
-                self.assertIn(
-                    params[3],
-                    {"foo", "@foo", "+foo"},
-                    m,
-                    fail_msg='Bad user list after user "foo" joined twice '
-                    "the same channel: should contain only user "
-                    '"foo" with an optional "+" or "@" prefix, but got: '
-                    "{msg}",
+                self.assertMessageMatch(
+                    m, params=["foo", StrRe(r"[=\*@]"), "#chan", StrRe("[@+]?foo")]
                 )
 
     def testJoinPartiallyInvalid(self):
diff --git a/irctest/server_tests/multi_prefix.py b/irctest/server_tests/multi_prefix.py
index ed57b9c..fd3d821 100644
--- a/irctest/server_tests/multi_prefix.py
+++ b/irctest/server_tests/multi_prefix.py
@@ -24,11 +24,6 @@ class MultiPrefixTestCase(cases.BaseServerTestCase):
 
         self.sendLine(1, "NAMES #chan")
         reply = self.getMessage(1)
-        self.assertMessageMatch(
-            reply,
-            command="353",
-            fail_msg="Expected NAMES response (353) with @+foo, got: {msg}",
-        )
         self.assertMessageMatch(
             reply,
             command="353",
@@ -47,9 +42,57 @@ class MultiPrefixTestCase(cases.BaseServerTestCase):
             8,
             "Expected WHO response (352) with 8 params, got: {msg}".format(msg=msg),
         )
-        self.assertTrue(
-            "@+" in msg.params[6],
+        self.assertIn(
+            "@+",
+            msg.params[6],
             'Expected WHO response (352) with "@+" in param 7, got: {msg}'.format(
                 msg=msg
             ),
         )
+
+    @cases.xfailIfSoftware(
+        ["irc2", "Bahamut"], "irc2 and Bahamut send a trailing space"
+    )
+    def testNoMultiPrefix(self):
+        """When not requested, only the highest prefix should be sent"""
+        self.connectClient("foo")
+        self.joinChannel(1, "#chan")
+        self.sendLine(1, "MODE #chan +v foo")
+        self.getMessages(1)
+
+        # TODO(dan): Make sure +v is voice
+
+        self.sendLine(1, "NAMES #chan")
+        reply = self.getMessage(1)
+        self.assertMessageMatch(
+            reply,
+            command="353",
+            params=["foo", ANYSTR, "#chan", "@foo"],
+            fail_msg="Expected NAMES response (353) with @foo, got: {msg}",
+        )
+        self.getMessages(1)
+
+        self.sendLine(1, "WHO #chan")
+        msg = self.getMessage(1)
+        self.assertEqual(
+            msg.command, "352", msg, fail_msg="Expected WHO response (352), got: {msg}"
+        )
+        self.assertGreaterEqual(
+            len(msg.params),
+            8,
+            "Expected WHO response (352) with 8 params, got: {msg}".format(msg=msg),
+        )
+        self.assertIn(
+            "@",
+            msg.params[6],
+            'Expected WHO response (352) with "@" in param 7, got: {msg}'.format(
+                msg=msg
+            ),
+        )
+        self.assertNotIn(
+            "+",
+            msg.params[6],
+            'Expected WHO response (352) with no "+" in param 7, got: {msg}'.format(
+                msg=msg
+            ),
+        )