diff --git a/.kokoro/presubmit/presubmit.cfg b/.kokoro/presubmit/presubmit.cfg
index ce3953120..ac4cc5847 100644
--- a/.kokoro/presubmit/presubmit.cfg
+++ b/.kokoro/presubmit/presubmit.cfg
@@ -3,5 +3,5 @@
 # Disable system tests.
 env_vars: {
     key: "NOX_SESSION"
-    value: "unit_noextras unit cover docs"
+    value: "unit_noextras unit cover docs docfx"
 }