diff --git a/src/Config.c b/src/Config.c
index 5c87c85..c19b5a8 100644
--- a/src/Config.c
+++ b/src/Config.c
@@ -230,3 +230,24 @@ ConfigLogLevelToSyslog(ConfigLogLevel level)
     }
     return LOG_INFO;
 }
+
+
+char *
+ConfigGetServerName(Db * db)
+{
+    char *name;
+
+    Config config;
+
+    ConfigLock(db, &config);
+    if (!config.ok)
+    {
+        return NULL;
+    }
+
+    name = StrDuplicate(config.serverName);
+
+    ConfigUnlock(&config);
+
+    return name;
+}
diff --git a/src/Room.c b/src/Room.c
index 65a7703..335eefe 100644
--- a/src/Room.c
+++ b/src/Room.c
@@ -43,6 +43,7 @@
 #include <Schema/PduV3.h>
 
 #include <CanonicalJson.h>
+#include <Config.h>
 #include <Parser.h>
 #include <State.h>
 #include <Event.h>
@@ -2215,25 +2216,6 @@ end:
     return ret;
 }
 
-static char *
-GetServerName(Db * db)
-{
-    char *name;
-
-    Config config;
-
-    ConfigLock(db, &config);
-    if (!config.ok)
-    {
-        return NULL;
-    }
-
-    name = StrDuplicate(config.serverName);
-
-    ConfigUnlock(&config);
-
-    return name;
-}
 bool
 RoomJoin(Room *room, User *user)
 {
@@ -2250,7 +2232,7 @@ RoomJoin(Room *room, User *user)
         return false;
     }
 
-    server = GetServerName(room->db);
+    server = ConfigGetServerName(room->db);
     if (!server)
     {
         return false;
diff --git a/src/Routes/RouteFetchEvent.c b/src/Routes/RouteFetchEvent.c
index 62f015b..1f49ed8 100644
--- a/src/Routes/RouteFetchEvent.c
+++ b/src/Routes/RouteFetchEvent.c
@@ -30,32 +30,14 @@
 #include <Cytoplasm/Json.h>
 #include <Cytoplasm/Str.h>
 
-#include <User.h>
-#include <Room.h>
 #include <string.h>
 
+#include <Config.h>
+#include <User.h>
+#include <Room.h>
+
 #include <Schema/Filter.h>
 
-static char *
-GetServerName(Db * db)
-{
-    char *name;
-
-    Config config;
-
-    ConfigLock(db, &config);
-    if (!config.ok)
-    {
-        return NULL;
-    }
-
-    name = StrDuplicate(config.serverName);
-
-    ConfigUnlock(&config);
-
-    return name;
-}
-
 ROUTE_IMPL(RouteFetchEvent, path, argp)
 {
     RouteArgs *args = argp;
@@ -90,7 +72,7 @@ ROUTE_IMPL(RouteFetchEvent, path, argp)
         goto finish;
     }
 
-    serverName = GetServerName(db);
+    serverName = ConfigGetServerName(db);
     if (!serverName)
     {
         HttpResponseStatus(args->context, HTTP_INTERNAL_SERVER_ERROR);
diff --git a/src/Routes/RouteFilter.c b/src/Routes/RouteFilter.c
index 55bfc32..89380fe 100644
--- a/src/Routes/RouteFilter.c
+++ b/src/Routes/RouteFilter.c
@@ -30,31 +30,13 @@
 #include <Cytoplasm/Json.h>
 #include <Cytoplasm/Str.h>
 
-#include <User.h>
 #include <string.h>
 
+#include <Config.h>
+#include <User.h>
+
 #include <Schema/Filter.h>
 
-static char *
-GetServerName(Db * db)
-{
-    char *name;
-
-    Config config;
-
-    ConfigLock(db, &config);
-    if (!config.ok)
-    {
-        return NULL;
-    }
-
-    name = StrDuplicate(config.serverName);
-
-    ConfigUnlock(&config);
-
-    return name;
-}
-
 ROUTE_IMPL(RouteFilter, path, argp)
 {
     RouteArgs *args = argp;
@@ -80,7 +62,7 @@ ROUTE_IMPL(RouteFilter, path, argp)
         return MatrixErrorCreate(M_UNKNOWN, NULL);
     }
 
-    serverName = GetServerName(db);
+    serverName = ConfigGetServerName(db);
     if (!serverName)
     {
         HttpResponseStatus(args->context, HTTP_INTERNAL_SERVER_ERROR);
diff --git a/src/Routes/RouteJoinRoom.c b/src/Routes/RouteJoinRoom.c
index 1069035..20c9d50 100644
--- a/src/Routes/RouteJoinRoom.c
+++ b/src/Routes/RouteJoinRoom.c
@@ -30,32 +30,14 @@
 #include <Cytoplasm/Json.h>
 #include <Cytoplasm/Str.h>
 
-#include <User.h>
-#include <Room.h>
 #include <string.h>
 
+#include <Config.h>
+#include <User.h>
+#include <Room.h>
+
 #include <Schema/Filter.h>
 
-static char *
-GetServerName(Db * db)
-{
-    char *name;
-
-    Config config;
-
-    ConfigLock(db, &config);
-    if (!config.ok)
-    {
-        return NULL;
-    }
-
-    name = StrDuplicate(config.serverName);
-
-    ConfigUnlock(&config);
-
-    return name;
-}
-
 ROUTE_IMPL(RouteJoinRoom, path, argp)
 {
     RouteArgs *args = argp;
@@ -97,7 +79,7 @@ ROUTE_IMPL(RouteJoinRoom, path, argp)
         goto finish;
     }
 
-    serverName = GetServerName(db);
+    serverName = ConfigGetServerName(db);
     if (!serverName)
     {
         HttpResponseStatus(args->context, HTTP_INTERNAL_SERVER_ERROR);
diff --git a/src/Routes/RouteJoinRoomAlias.c b/src/Routes/RouteJoinRoomAlias.c
index a3e23a3..1cd1e15 100644
--- a/src/Routes/RouteJoinRoomAlias.c
+++ b/src/Routes/RouteJoinRoomAlias.c
@@ -30,32 +30,14 @@
 #include <Cytoplasm/Json.h>
 #include <Cytoplasm/Str.h>
 
-#include <User.h>
-#include <Room.h>
 #include <string.h>
 
+#include <Config.h>
+#include <User.h>
+#include <Room.h>
+
 #include <Schema/Filter.h>
 
-static char *
-GetServerName(Db * db)
-{
-    char *name;
-
-    Config config;
-
-    ConfigLock(db, &config);
-    if (!config.ok)
-    {
-        return NULL;
-    }
-
-    name = StrDuplicate(config.serverName);
-
-    ConfigUnlock(&config);
-
-    return name;
-}
-
 ROUTE_IMPL(RouteJoinRoomAlias, path, argp)
 {
     RouteArgs *args = argp;
@@ -112,7 +94,7 @@ ROUTE_IMPL(RouteJoinRoomAlias, path, argp)
         goto finish;
     }
 
-    serverName = GetServerName(db);
+    serverName = ConfigGetServerName(db);
     if (!serverName)
     {
         HttpResponseStatus(args->context, HTTP_INTERNAL_SERVER_ERROR);
diff --git a/src/Routes/RouteMessages.c b/src/Routes/RouteMessages.c
index fa89694..8ba3f9b 100644
--- a/src/Routes/RouteMessages.c
+++ b/src/Routes/RouteMessages.c
@@ -30,6 +30,7 @@
 #include <Cytoplasm/Json.h>
 #include <Cytoplasm/Str.h>
 
+#include <Config.h>
 #include <User.h>
 #include <Room.h>
 
@@ -38,26 +39,6 @@
 
 #include <Schema/Filter.h>
 
-static char *
-GetServerName(Db * db)
-{
-    char *name;
-
-    Config config;
-
-    ConfigLock(db, &config);
-    if (!config.ok)
-    {
-        return NULL;
-    }
-
-    name = StrDuplicate(config.serverName);
-
-    ConfigUnlock(&config);
-
-    return name;
-}
-
 ROUTE_IMPL(RouteMessages, path, argp)
 {
     RouteArgs *args = argp;
@@ -102,7 +83,7 @@ ROUTE_IMPL(RouteMessages, path, argp)
         goto finish;
     }
 
-    serverName = GetServerName(db);
+    serverName = ConfigGetServerName(db);
     if (!serverName)
     {
         HttpResponseStatus(args->context, HTTP_INTERNAL_SERVER_ERROR);
diff --git a/src/Routes/RouteSendEvent.c b/src/Routes/RouteSendEvent.c
index a4ad505..784f228 100644
--- a/src/Routes/RouteSendEvent.c
+++ b/src/Routes/RouteSendEvent.c
@@ -30,32 +30,14 @@
 #include <Cytoplasm/Json.h>
 #include <Cytoplasm/Str.h>
 
-#include <User.h>
-#include <Room.h>
 #include <string.h>
 
+#include <Config.h>
+#include <User.h>
+#include <Room.h>
+
 #include <Schema/Filter.h>
 
-static char *
-GetServerName(Db * db)
-{
-    char *name;
-
-    Config config;
-
-    ConfigLock(db, &config);
-    if (!config.ok)
-    {
-        return NULL;
-    }
-
-    name = StrDuplicate(config.serverName);
-
-    ConfigUnlock(&config);
-
-    return name;
-}
-
 ROUTE_IMPL(RouteSendEvent, path, argp)
 {
     RouteArgs *args = argp;
@@ -93,7 +75,7 @@ ROUTE_IMPL(RouteSendEvent, path, argp)
         goto finish;
     }
 
-    serverName = GetServerName(db);
+    serverName = ConfigGetServerName(db);
     if (!serverName)
     {
         HttpResponseStatus(args->context, HTTP_INTERNAL_SERVER_ERROR);
@@ -209,7 +191,7 @@ ROUTE_IMPL(RouteSendState, path, argp)
         goto finish;
     }
 
-    serverName = GetServerName(db);
+    serverName = ConfigGetServerName(db);
     if (!serverName)
     {
         HttpResponseStatus(args->context, HTTP_INTERNAL_SERVER_ERROR);
diff --git a/src/Routes/RouteUserProfile.c b/src/Routes/RouteUserProfile.c
index a4fc870..376114b 100644
--- a/src/Routes/RouteUserProfile.c
+++ b/src/Routes/RouteUserProfile.c
@@ -28,10 +28,52 @@
 
 #include <Cytoplasm/HashMap.h>
 #include <Cytoplasm/Memory.h>
-#include <User.h>
 #include <Cytoplasm/Json.h>
 #include <Cytoplasm/Str.h>
 
+#include <Config.h>
+#include <User.h>
+#include <Room.h>
+
+static void
+SendMembership(Db *db, User *user)
+{
+    char *displayname = UserGetProfile(user, "displayname");
+    char *avatar_url = UserGetProfile(user, "avatar_url");
+    Array *joins = UserListJoins(user);
+    size_t i;
+
+    char *server_name = ConfigGetServerName(db);
+
+    CommonID *user_id = UserIdParse(UserGetName(user), server_name);
+    char *sender = ParserRecomposeCommonID(*user_id);
+    Free(server_name);
+
+    for (i = 0; i < ArraySize(joins); i++)
+    {
+        char *room_id = ArrayGet(joins, i);
+        Room *room = RoomLock(db, room_id);
+        HashMap *content = HashMapCreate();
+        HashMap *membership = RoomEventCreate(
+            sender, "m.room.member", sender,
+            content
+        );
+
+        HashMapSet(content, "membership", JsonValueString("join"));
+        HashMapSet(content, "displayname", JsonValueString(displayname));
+        HashMapSet(content, "avatar_url", JsonValueString(avatar_url));
+
+        JsonFree(RoomEventSend(room, membership));
+        JsonFree(membership);
+        
+        RoomUnlock(room);
+    }
+
+    UserFreeList(joins);
+    UserIdFree(user_id);
+    Free(sender);
+}
+
 ROUTE_IMPL(RouteUserProfile, path, argp)
 {
     RouteArgs *args = argp;
@@ -142,6 +184,8 @@ ROUTE_IMPL(RouteUserProfile, path, argp)
                     response = MatrixErrorCreate(M_UNKNOWN_TOKEN, NULL);
                     goto finish;
                 }
+
+                /* TODO: This may change in the future. */
                 entry = ArrayGet(path, 1);
                 if (StrEquals(entry, "displayname") ||
                     StrEquals(entry, "avatar_url"))
@@ -153,6 +197,7 @@ ROUTE_IMPL(RouteUserProfile, path, argp)
                         /* TODO: Make UserSetProfile notify other parties of 
                          * the change */
                         UserSetProfile(user, entry, value);
+                        SendMembership(db, user);
                         response = HashMapCreate();
                         goto finish;
                     }
diff --git a/src/User.c b/src/User.c
index 8e12773..3209ba8 100644
--- a/src/User.c
+++ b/src/User.c
@@ -83,7 +83,7 @@ UserValidate(char *localpart, char *domain)
 bool
 UserHistoricalValidate(char *localpart, char *domain)
 {
-    size_t maxLen = 255 - strlen(domain) - 1;
+    size_t maxLen = 255 - (domain ? strlen(domain) : 0) - 1;
     size_t i = 0;
 
     while (localpart[i])
@@ -949,7 +949,7 @@ UserIdParse(char *id, char *defaultServer)
         userId->local = StrDuplicate(id);
         ParseServerPart(defaultServer, &userId->server);
     }
-
+    userId->sigil = '@';
     server = ParserRecomposeServerPart(userId->server);
     if (!UserHistoricalValidate(userId->local, server))
     {
diff --git a/src/include/Config.h b/src/include/Config.h
index 6d925b7..530ac79 100644
--- a/src/include/Config.h
+++ b/src/include/Config.h
@@ -98,6 +98,16 @@ extern void ConfigLock(Db *, Config *);
  */
 extern int ConfigUnlock(Config *);
 
+/**
+ * Returns the configuration's server name from a database.
+ * This is an utility function that masks behind
+ * .Fn ConfigLock ,
+ * and the value returned lives on the heap, and must be freed 
+ * with 
+ * .Fn Free .
+ */
+extern char * ConfigGetServerName(Db *);
+
 /**
  * Converts a ConfigLogLevel into a valid syslog level.
  */