diff --git a/discord/client.py b/discord/client.py
index 02bd5d6fe..d738e7bf2 100644
--- a/discord/client.py
+++ b/discord/client.py
@@ -1398,7 +1398,7 @@ class Client:
         yield from self.http.unban(user.id, server.id)
 
     @asyncio.coroutine
-    def server_voice_state(self, member, *, mute=False, deafen=False):
+    def server_voice_state(self, member, *, mute=None, deafen=None):
         """|coro|
 
         Server mutes or deafens a specific :class:`Member`.
@@ -1413,9 +1413,9 @@ class Client:
         -----------
         member : :class:`Member`
             The member to unban from their server.
-        mute : bool
+        mute: Optional[bool]
             Indicates if the member should be server muted or un-muted.
-        deafen : bool
+        deafen: Optional[bool]
             Indicates if the member should be server deafened or un-deafened.
 
         Raises
diff --git a/discord/http.py b/discord/http.py
index 992d76350..192337fe8 100644
--- a/discord/http.py
+++ b/discord/http.py
@@ -307,12 +307,15 @@ class HTTPClient:
         url = '{0.GUILDS}/{1}/bans/{2}'.format(self, guild_id, user_id)
         return self.delete(url, bucket=_func_())
 
-    def server_voice_state(self, user_id, guild_id, *, mute=False, deafen=False):
+    def server_voice_state(self, user_id, guild_id, *, mute=None, deafen=None):
         url = '{0.GUILDS}/{1}/members/{2}'.format(self, guild_id, user_id)
-        payload = {
-            'mute': mute,
-            'deafen': deafen
-        }
+        payload = {}
+        if mute is not None:
+            payload['mute'] = mute
+
+        if deafen is not None:
+            payload['deaf'] = deafen
+
         return self.patch(url, json=payload, bucket='members:' + str(guild_id))
 
     def edit_profile(self, password, username, avatar, **fields):