diff --git a/.kokoro/build-with-appengine.sh b/.kokoro/build-with-appengine.sh
index 2034649426..306393f52a 100755
--- a/.kokoro/build-with-appengine.sh
+++ b/.kokoro/build-with-appengine.sh
@@ -19,7 +19,7 @@ set -e;
 export GCLOUD_PROJECT=nodejs-docs-samples-tests
 
 # Activate mocha config
-export MOCHA_REPORTER_OUTPUT=sponge_log.xml
+export MOCHA_REPORTER_OUTPUT=${PROJECT}_sponge_log.xml
 export MOCHA_REPORTER=xunit
 pushd github/nodejs-docs-samples
 mv .kokoro/.mocharc.js .
diff --git a/.kokoro/build-with-run.sh b/.kokoro/build-with-run.sh
index 7ede33d250..bfe3bb9aa2 100755
--- a/.kokoro/build-with-run.sh
+++ b/.kokoro/build-with-run.sh
@@ -17,7 +17,7 @@
 set -eo pipefail
 
 # Activate mocha config
-export MOCHA_REPORTER_OUTPUT=sponge_log.xml
+export MOCHA_REPORTER_OUTPUT=${PROJECT}_sponge_log.xml
 export MOCHA_REPORTER=xunit
 pushd github/nodejs-docs-samples
 mv .kokoro/.mocharc.js .
diff --git a/.kokoro/build.sh b/.kokoro/build.sh
index 48aec83498..9df9f923b0 100755
--- a/.kokoro/build.sh
+++ b/.kokoro/build.sh
@@ -72,7 +72,7 @@ export BOT_ACCESS_TOKEN=${KOKORO_GFILE_DIR}/secrets-slack-bot-access-token.txt
 export CHANNEL=${KOKORO_GFILE_DIR}/secrets-slack-channel-id.txt
 
 # Activate mocha config
-export MOCHA_REPORTER_OUTPUT=sponge_log.xml
+export MOCHA_REPORTER_OUTPUT=${PROJECT}_sponge_log.xml
 export MOCHA_REPORTER=xunit
 pushd github/nodejs-docs-samples
 mv .kokoro/.mocharc.js .