diff --git a/buildscripts/resmokelib/testing/fixtures/shardedcluster.py b/buildscripts/resmokelib/testing/fixtures/shardedcluster.py
index 35b9b4cba4..c7c9c0d80e 100644
--- a/buildscripts/resmokelib/testing/fixtures/shardedcluster.py
+++ b/buildscripts/resmokelib/testing/fixtures/shardedcluster.py
@@ -568,7 +568,7 @@ class MongosLauncher(object):
                                                          self.fixturelib.make_historic({}))
 
         if self.config.MONGOS_SET_PARAMETERS is not None:
-            suite_set_parameters.update(yaml.safe_load(self.config.MONGOS_SET_PARAMETERS))
+            suite_set_parameters.update(self.fixturelib.make_historic(yaml.safe_load(self.config.MONGOS_SET_PARAMETERS)))
 
         # Set default log verbosity levels if none were specified.
         if "logComponentVerbosity" not in suite_set_parameters: