diff --git a/mpi/scanned_days_manager.py b/mpi/scanned_days_manager.py
index 432f8e2f992f8143c44b2ebdb5ca3d6b9696a55a..36a98384e2ddaebbdc736f95f98b934dc8fa0d7a 100644
--- a/mpi/scanned_days_manager.py
+++ b/mpi/scanned_days_manager.py
@@ -82,12 +82,14 @@ class ScannedDaysManager(object):
             self.__add_entry(self.to_process, chunk, template)
 
     def remove_chunk(self, chunk):
-        self.chunks.remove(chunk)
+        if chunk in self.chunks:
+            self.chunks.remove(chunk)
         if chunk in self.to_process:
             del self.to_process[chunk]
 
     def remove_template(self, template):
-        self.templates.remove(template)
+        if template in self.templates:
+            self.templates.remove(template)
         for chunk in self.to_process[:]:
             self.__remove_entry(self.to_process, chunk, template)