diff --git a/.evergreen/run-perf-tests.sh b/.evergreen/run-perf-tests.sh
index 41f154b73..cdf598c3b 100644
--- a/.evergreen/run-perf-tests.sh
+++ b/.evergreen/run-perf-tests.sh
@@ -22,7 +22,7 @@ pip install simplejson
 
 python setup.py build_ext -i
 start_time=$(date +%s)
-python test/performance/perf_test.py
+python test/performance/perf_test.py --locals
 end_time=$(date +%s)
 elapsed_secs=$((end_time-start_time))
 
diff --git a/test/performance/perf_test.py b/test/performance/perf_test.py
index 4a2ba2fea..9f6e268df 100644
--- a/test/performance/perf_test.py
+++ b/test/performance/perf_test.py
@@ -399,7 +399,7 @@ def insert_json_file_with_file_id(filename):
 
 def read_json_file(filename):
     coll = proc_client.perftest.corpus
-    temp = tempfile.TemporaryFile()
+    temp = tempfile.TemporaryFile(mode='w')
     try:
         temp.writelines(
             [json.dumps(doc) + '\n' for