diff --git a/bin/slackcat b/bin/slackcat
index 7700c92..7388142 100755
--- a/bin/slackcat
+++ b/bin/slackcat
@@ -22,6 +22,10 @@ class Slackcat
     @channels ||= get_objects('channels.list', 'channels')
   end
 
+  def channel_by(name)
+    channels().find { |channel| channel['name'] == name }
+  end
+
   def groups
     @groups ||= get_objects('groups.list', 'groups')
   end
@@ -114,8 +118,15 @@ if opts.values_at(:channels, :groups, :users).all?(&:empty?)
 end
 
 ## translate destination names into slack ids
-channels = opts[:channels].split(/[\s,]+/).map do |name|
-  slack.channels.find { |channel| channel['name'] == name }.fetch('id')
+individual_channel_names = opts[:channels].split(/[\s,]+/)
+existing_channel_names = individual_channel_names.select {|name| slack.channel_by(name)}
+
+(individual_channel_names - existing_channel_names).each do |name|
+  puts "skipping channel #{name}: not available (maybe use -g for group?)"
+end
+
+channels = existing_channel_names.map do |name|
+  slack.channel_by(name).fetch('id')
 end
 
 groups = opts[:groups].split(/[\s,]+/).map do |name|