diff --git a/src/Parser.c b/src/Parser.c
index e514c6d..0e5f1a9 100644
--- a/src/Parser.c
+++ b/src/Parser.c
@@ -267,6 +267,26 @@ ParseCommonID(char *str, CommonID *id)
     
     switch (sigil)
     {
+        case '$':
+            /* For event IDs, it depends on the version, so we're just 
+             * accepting it all. */
+            if (!ParseUserLocalpart(&str, &id->local))
+            {
+                return 0;
+            }
+            if (*str == ':')
+            {
+                (*str)++;
+                if (!ParseServerName(&str, &id->server))
+                {
+                    Free(id->local);
+                    id->local = NULL;
+                    return 0;
+                }
+                return 1;
+            }
+            break;
+        case '!':
         case '#': /* It seems like the localpart should be the same as the 
                      user's: everything, except ':'. */
         case '@':
@@ -280,7 +300,6 @@ ParseCommonID(char *str, CommonID *id)
                 id->local = NULL;
                 return 0;
             }
-            /* TODO: Match whenever str is valid. */
             if (!ParseServerName(&str, &id->server))
             {
                 Free(id->local);
diff --git a/src/Routes/RouteAliasDirectory.c b/src/Routes/RouteAliasDirectory.c
index 7a4772f..5d447f8 100644
--- a/src/Routes/RouteAliasDirectory.c
+++ b/src/Routes/RouteAliasDirectory.c
@@ -41,7 +41,7 @@ ROUTE_IMPL(RouteAliasDirectory, path, argp)
     HashMap *response;
 
     Db *db = args->matrixArgs->db;
-    DbRef *ref;
+    DbRef *ref = NULL;
     HashMap *aliases;
     JsonValue *val;
 
@@ -49,17 +49,23 @@ ROUTE_IMPL(RouteAliasDirectory, path, argp)
     char *msg;
     User *user = NULL;
 
-    CommonID commonID;
+    CommonID aliasID;
+    CommonID roomID;
     Config *config;
 
-    commonID.sigil = '\0';
-    commonID.local = NULL;
-    commonID.server.hostname = NULL;
-    commonID.server.port = NULL;
+    aliasID.sigil = '\0';
+    aliasID.local = NULL;
+    aliasID.server.hostname = NULL;
+    aliasID.server.port = NULL;
+
+    roomID.sigil = '\0';
+    roomID.local = NULL;
+    roomID.server.hostname = NULL;
+    roomID.server.port = NULL;
 
     config = ConfigLock(db);
 
-    if (!ParseCommonID(alias, &commonID) || commonID.sigil != '#')
+    if (!ParseCommonID(alias, &aliasID) || aliasID.sigil != '#')
     {
         msg = "Invalid room alias.";
         HttpResponseStatus(args->context, HTTP_BAD_REQUEST);
@@ -118,7 +124,7 @@ ROUTE_IMPL(RouteAliasDirectory, path, argp)
                 /* Check for server name. 
                  * TODO: Take the port into account, that might need a 
                  * refactor for it to use a ServerPart */
-                if (!StrEquals(commonID.server.hostname, config->serverName))
+                if (!StrEquals(aliasID.server.hostname, config->serverName))
                 {
                     HttpResponseStatus(args->context, HTTP_BAD_REQUEST);
                     response = MatrixErrorCreate(M_INVALID_PARAM, "Invalid servername");
@@ -149,6 +155,13 @@ ROUTE_IMPL(RouteAliasDirectory, path, argp)
 
                 /* TODO: Validate room ID to make sure it is well
                  * formed. */
+                if (!ParseCommonID(JsonValueAsString(HashMapGet(request, "room_id")), &roomID) || aliasID.sigil != '!')
+                {
+                    msg = "Invalid room ID.";
+                    HttpResponseStatus(args->context, HTTP_BAD_REQUEST);
+                    response = MatrixErrorCreate(M_INVALID_PARAM, msg);
+                    goto finish;
+                }
 
                 newAlias = HashMapCreate();
                 HashMapSet(newAlias, "createdBy", JsonValueString(UserGetName(user)));
@@ -185,7 +198,8 @@ ROUTE_IMPL(RouteAliasDirectory, path, argp)
     }
 
 finish:
-    CommonIDFree(commonID);
+    CommonIDFree(aliasID);
+    CommonIDFree(roomID);
     ConfigUnlock(config);
     UserUnlock(user);
     DbUnlock(db, ref);