diff --git a/pisi/component.py b/pisi/component.py
index 7a5bf4ca..f27daf7a 100644
--- a/pisi/component.py
+++ b/pisi/component.py
@@ -116,7 +116,8 @@ class ComponentDB(object):
     def add_package(self, component_name, package, txn = None):
         def proc(txn):
             component = self.get_component(component_name, txn)
-            component.packages.append(package)
+            if not package in component.packages:
+                component.packages.append(package)
             self.d.put(component_name, component, txn) # update
         self.d.txn_proc(proc, txn)