diff --git a/openmc/summary.py b/openmc/summary.py
index f17c0c8f9..9609a866b 100644
--- a/openmc/summary.py
+++ b/openmc/summary.py
@@ -564,8 +564,9 @@ class Summary(object):
 
                 # Read in distribcell paths
                 if filter_type == 'distribcell':
-                    new_filter.distribcell_paths = \
-                        self._f['{0}/paths'.format(subsubbase)][...]
+                    paths = self._f['{0}/paths'.format(subsubbase)][...]
+                    paths = [path.decode() for path in paths]
+                    new_filter.distribcell_paths = paths
 
                 # Add Filter to the Tally
                 tally.filters.append(new_filter)
diff --git a/tests/run_tests.py b/tests/run_tests.py
index 48fc23d4a..ed6ff0c20 100755
--- a/tests/run_tests.py
+++ b/tests/run_tests.py
@@ -363,10 +363,14 @@ sourcepoint_batch|statepoint_interval|survival_biasing|\
 tally_assumesep|translation|uniform_fs|universe|void"
 
 # Delete items of dictionary if valgrind or coverage and not in script mode
+to_delete = []
 if not script_mode:
     for key in tests:
         if re.search('valgrind|coverage', key):
-            del tests[key]
+            to_delete.append(key)
+
+for key in to_delete:
+    del tests[key]
 
 # Check if tests empty
 if len(list(tests.keys())) == 0: