diff --git a/lib/bot.js b/lib/bot.js
index 8417047a..7eaf0312 100644
--- a/lib/bot.js
+++ b/lib/bot.js
@@ -125,19 +125,24 @@ class Bot {
       this.sendToDiscord(author, to, `*${text}*`);
     });
 
-    this.ircClient.on('join', (channel, nick) => {
+    this.ircClient.on('join', (channelName, nick) => {
+      logger.debug('Received join:', channelName, nick);
       if (!this.ircStatusNotices) return;
       if (nick === this.nickname && !this.announceSelfJoin) return;
+      const channel = channelName.toLowerCase();
       // self-join is announced before names (which includes own nick)
       // so don't add nick to channelUsers
       if (nick !== this.nickname) this.channelUsers[channel].add(nick);
       this.sendExactToDiscord(channel, `*${nick}* has joined the channel`);
     });
 
-    this.ircClient.on('part', (channel, nick, reason) => {
+    this.ircClient.on('part', (channelName, nick, reason) => {
+      logger.debug('Received part:', channelName, nick, reason);
       if (!this.ircStatusNotices) return;
+      const channel = channelName.toLowerCase();
       // remove list of users when no longer in channel (as it will become out of date)
       if (nick === this.nickname) {
+        logger.debug('Deleting channelUsers as bot parted:', channel);
         delete this.channelUsers[channel];
         return;
       }
@@ -146,15 +151,19 @@ class Bot {
     });
 
     this.ircClient.on('quit', (nick, reason, channels) => {
+      logger.debug('Received quit:', nick, channels);
       if (!this.ircStatusNotices || nick === this.nickname) return;
-      channels.forEach((channel) => {
+      channels.forEach((channelName) => {
+        const channel = channelName.toLowerCase();
         if (!this.channelUsers[channel].delete(nick)) return;
         this.sendExactToDiscord(channel, `*${nick}* has quit (${reason})`);
       });
     });
 
-    this.ircClient.on('names', (channel, nicks) => {
+    this.ircClient.on('names', (channelName, nicks) => {
+      logger.debug('Received names:', channelName, nicks);
       if (!this.ircStatusNotices) return;
+      const channel = channelName.toLowerCase();
       this.channelUsers[channel] = new Set(Object.keys(nicks));
     });
 
diff --git a/test/bot-events.test.js b/test/bot-events.test.js
index 0766b482..5e7e371e 100644
--- a/test/bot-events.test.js
+++ b/test/bot-events.test.js
@@ -135,6 +135,16 @@ describe('Bot Events', function () {
     bot.channelUsers.should.deep.equal({ '#channel': channelNicks });
   });
 
+  it('should lowercase the channelUsers mapping', function () {
+    const bot = createBot({ ...config, ircStatusNotices: true });
+    bot.connect();
+    const channel = '#channelName';
+    const nicks = { [bot.nickname]: '' };
+    bot.ircClient.emit('names', channel, nicks);
+    const channelNicks = new Set([bot.nickname]);
+    bot.channelUsers.should.deep.equal({ '#channelname': channelNicks });
+  });
+
   it('should send join messages to discord when config enabled', function () {
     const bot = createBot({ ...config, ircStatusNotices: true });
     bot.connect();
@@ -222,6 +232,22 @@ describe('Bot Events', function () {
     bot.sendExactToDiscord.getCall(1).args.should.deep.equal([channel3, text]);
   });
 
+  it('should not crash with join/part/quit messages and weird channel casing', function () {
+    const bot = createBot({ ...config, ircStatusNotices: true });
+    bot.connect();
+
+    function wrap() {
+      const nick = 'user';
+      const reason = 'Leaving';
+      bot.ircClient.emit('names', '#Channel', { [bot.nickname]: '' });
+      bot.ircClient.emit('join', '#cHannel', nick);
+      bot.ircClient.emit('part', '#chAnnel', nick, reason);
+      bot.ircClient.emit('join', '#chaNnel', nick);
+      bot.ircClient.emit('quit', nick, reason, ['#chanNel']);
+    }
+    (wrap).should.not.throw();
+  });
+
   it('should be possible to disable join/part/quit messages', function () {
     const bot = createBot({ ...config, ircStatusNotices: false });
     bot.connect();