diff --git a/lib/poepod/cli.rb b/lib/poepod/cli.rb
index 3139b83..d8fa27f 100644
--- a/lib/poepod/cli.rb
+++ b/lib/poepod/cli.rb
@@ -12,6 +12,12 @@ class Cli < Thor
     def concat(directory, output_file = nil)
       dir_path = Pathname.new(directory)
 
+      # Check if the directory exists
+      unless dir_path.directory?
+        puts "Error: Directory '#{directory}' does not exist."
+        exit(1)
+      end
+
       dir_path = dir_path.expand_path unless dir_path.absolute?
 
       output_file ||= "#{dir_path.basename}.txt"