diff --git a/scripts/ci/env.sh b/scripts/ci/env.sh
index b820e90d88..7c597f8b54 100755
--- a/scripts/ci/env.sh
+++ b/scripts/ci/env.sh
@@ -36,7 +36,9 @@ fi
 
 setEnvVar NODE_VERSION 6.9.5
 setEnvVar YARN_VERSION 1.0.2
-setEnvVar CHROMIUM_VERSION 499098 # Chrome 62 linux stable, see https://www.chromium.org/developers/calendar
+# Pin to a Chromium version that does not cause the aio e2e tests to flake. (See https://github.com/angular/angular/pull/20403.)
+# Revision 494239 (which was part of Chrome 62.0.3186.0) is the last version that does not cause flakes. (Latest revision checked: 508578)
+setEnvVar CHROMIUM_VERSION 494239 # Chrome 62 linux stable, see https://www.chromium.org/developers/calendar
 setEnvVar CHROMEDRIVER_VERSION_ARG "--versions.chrome 2.33"
 setEnvVar SAUCE_CONNECT_VERSION 4.4.9
 setEnvVar PROJECT_ROOT $(cd ${thisDir}/../..; pwd)