diff --git a/transfer_service/tape_client.py b/transfer_service/tape_client.py
index a080dce0603e2a1bcc05acac7df03cc549115ed5..36ece40c43360306f2d71129e2c40c5e4f7f00fd 100644
--- a/transfer_service/tape_client.py
+++ b/transfer_service/tape_client.py
@@ -57,6 +57,7 @@ class TapeClient(object):
         else:
             sys.exit("cmd_exit_code = FAILURE")
             
+    # Copies files/dirs recursively by passing their absolute paths        
     def copy(self, srcPath, destPath):
         self.scp = scp.SCPClient(self.client.get_transport())
         print(f"Copying {srcPath} in {destPath}")
@@ -65,7 +66,7 @@ class TapeClient(object):
         elif os.path.isfile(srcPath):
             self.scp.put(srcPath, destPath)
         else:
-            sys.exit("This is a special file!")
+            sys.exit("FATAL: invalid file/dir.")
         self.scp.close()    
     
     # Closes the connection