diff --git a/README.md b/README.md
index 2eea357..e4677f2 100644
--- a/README.md
+++ b/README.md
@@ -18,11 +18,11 @@ Phase 2:
 * [x] More useful spam in management room
 * [ ] Command to import ACLs, etc from rooms
 * [ ] Vet rooms on startup option
-* [ ] Room upgrade handling (both protected+list rooms)
 * [ ] Command to actually unban users (instead of leaving them stuck)
 
 Phase 3:
 * [ ] Synapse antispam module
+* [ ] Room upgrade handling (both protected+list rooms)
 * [ ] Support community-defined scopes? (ie: no hardcoded config)
 * [ ] Riot hooks (independent of mjolnir?)
 
diff --git a/config/default.yaml b/config/default.yaml
index 7c864fd..3a567ce 100644
--- a/config/default.yaml
+++ b/config/default.yaml
@@ -33,6 +33,10 @@ managementRoom: "#moderators:example.org"
 # Set to false to make the management room a bit quieter.
 verboseLogging: true
 
+# Set to false to disable synchronizing the ban lists on startup. If true, this
+# is the same as running !mjolnir sync immediately after startup.
+syncOnStartup: true
+
 # The room ID or alias where the bot's own personal ban list is kept. This is
 # where the commands to manage a ban list end up being routed to. Note that
 # this room is NOT automatically added to the banLists list below - you will
diff --git a/src/Mjolnir.ts b/src/Mjolnir.ts
index 12da537..26037b1 100644
--- a/src/Mjolnir.ts
+++ b/src/Mjolnir.ts
@@ -20,6 +20,7 @@ import { applyServerAcls } from "./actions/ApplyAcl";
 import { RoomUpdateError } from "./models/RoomUpdateError";
 import { COMMAND_PREFIX, handleCommand } from "./commands/CommandHandler";
 import { applyUserBans } from "./actions/ApplyBan";
+import config from "./config";
 
 export class Mjolnir {
 
@@ -64,7 +65,12 @@ export class Mjolnir {
     }
 
     public start() {
-        return this.client.start();
+        return this.client.start().then(() => {
+            if (config.syncOnStartup) {
+                this.client.sendNotice(this.managementRoomId, "Syncing lists...");
+                return this.syncLists();
+            }
+        });
     }
 
     public async syncLists() {
diff --git a/src/config.ts b/src/config.ts
index ae06943..4d7d44c 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -28,6 +28,7 @@ interface IConfig {
     autojoin: boolean;
     managementRoom: string;
     verboseLogging: boolean;
+    syncOnStartup: boolean;
     publishedBanListRoom: string;
     protectedRooms: string[]; // matrix.to urls
     banLists: string[]; // matrix.to urls