diff --git a/Dockerfile b/Dockerfile
index 788c0cd2..5fc00b15 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM quay.io/broadinstitute/viral-core:2.2.1
+FROM quay.io/broadinstitute/viral-core:2.2.3
 
 LABEL maintainer "viral-ngs@broadinstitute.org"
 
diff --git a/conftest.py b/conftest.py
index b5b6f937..87bd0dc6 100644
--- a/conftest.py
+++ b/conftest.py
@@ -166,13 +166,13 @@ def pytest_terminal_summary(self, terminalreporter, exitstatus):
         if self.durations is None:
             return
 
-        writer = terminalreporter.writer
+        writer = terminalreporter
 
         slowest = sorted(self.stats.items(), key=operator.itemgetter(1), reverse=True)
         if not self.durations:
-            writer.sep("=", "slowest fixture durations")
+            writer.write_sep("=", "slowest fixture durations")
         else:
-            writer.sep("=", "slowest %s fixture durations" % self.durations)
+            writer.write_sep("=", "slowest %s fixture durations" % self.durations)
             slowest = slowest[:self.durations]