diff --git a/pandaharvester/harvesterzipper/simple_zipper.py b/pandaharvester/harvesterzipper/simple_zipper.py
index ca558ff1..fcdb0344 100644
--- a/pandaharvester/harvesterzipper/simple_zipper.py
+++ b/pandaharvester/harvesterzipper/simple_zipper.py
@@ -8,6 +8,7 @@
 
 # simple plugin for zipper
 class SimpleZipper(BaseZipper):
+    """Simple zipper plugin that zips output files synchronously."""
     # constructor
     def __init__(self, **kwarg):
         BaseZipper.__init__(self, **kwarg)
diff --git a/pandaharvester/harvesterzipper/ssh_zipper.py b/pandaharvester/harvesterzipper/ssh_zipper.py
index d0322290..c1ebf806 100644
--- a/pandaharvester/harvesterzipper/ssh_zipper.py
+++ b/pandaharvester/harvesterzipper/ssh_zipper.py
@@ -8,6 +8,7 @@
 
 # ssh plugin for zipper
 class SshZipper(BaseZipper):
+    """SSH zipper plugin that zips output files via SSH connection."""
     # constructor
     def __init__(self, **kwarg):
         BaseZipper.__init__(self, **kwarg)