diff --git a/src/bin/pungi.py b/src/bin/pungi.py
index a80e29df..27c062f8 100755
--- a/src/bin/pungi.py
+++ b/src/bin/pungi.py
@@ -87,6 +87,8 @@ def main():
         config.set('pungi', 'full_archlist', "True")
     if opts.arch:
         config.set('pungi', 'arch', opts.arch)
+    if opts.lookaside_repos:
+        config.set('pungi', 'lookaside_repos', " ".join(opts.lookaside_repos))
 
     # Actually do work.
     mypungi = pypungi.Pungi(config, ksparser)
@@ -222,6 +224,8 @@ if __name__ == '__main__':
           help='Use the full arch list for x86_64 (include i686, i386, etc.)')
         parser.add_option("--arch",
           help='Override default (uname based) arch')
+        parser.add_option("--lookaside-repo", action="append", dest="lookaside_repos", metavar="NAME",
+          help='Specify lookaside repo name(s) (packages will used for depsolving but not be included in the output)')
 
         parser.add_option("-c", "--config", dest="config",
           help='Path to kickstart config file')
diff --git a/src/pypungi/__init__.py b/src/pypungi/__init__.py
index 893874d0..1641fa33 100644
--- a/src/pypungi/__init__.py
+++ b/src/pypungi/__init__.py
@@ -143,6 +143,7 @@ class Pungi(pypungi.PungiBase):
         self.resolved_deps = {} # list the deps we've already resolved, short circuit.
         self.excluded_pkgs = {} # list the packages we've already excluded.
         self.seen_pkgs = {}     # list the packages we've already seen so we can check all deps only once
+        self.lookaside_repos = self.config.get('pungi', 'lookaside_repos').split(" ")
 
     def _add_yum_repo(self, name, url, mirrorlist=False, groups=True,
                       cost=1000, includepkgs=[], excludepkgs=[],
@@ -848,7 +849,7 @@ class Pungi(pypungi.PungiBase):
 
     def _listPackages(self, polist):
         """Cycle through the list of packages and return their paths."""
-        return [ os.path.join(pkg.basepath or "", pkg.relativepath) for pkg in polist ]
+        return [ os.path.join(pkg.basepath or "", pkg.relativepath) for pkg in polist if pkg.repoid not in self.lookaside_repos ]
 
     def listPackages(self):
         """Cycle through the list of RPMs and return their paths."""
diff --git a/src/pypungi/config.py b/src/pypungi/config.py
index 4e076ded..81f744a1 100644
--- a/src/pypungi/config.py
+++ b/src/pypungi/config.py
@@ -46,4 +46,5 @@ class Config(SafeConfigParser):
         self.set('pungi', 'isfinal', "False")
         self.set('pungi', 'nohash', "False")
         self.set('pungi', 'full_archlist', "False")
+        self.set('pungi', 'lookaside_repos', '')