diff --git a/cloudbuild.yml b/cloudbuild.yml
index 4824a4906be..30c0ac949cc 100644
--- a/cloudbuild.yml
+++ b/cloudbuild.yml
@@ -22,6 +22,7 @@ steps:
   id: 'tfjs-core'
   args: ['./scripts/run-build.sh', 'tfjs-core']
   waitFor: ['find-affected-packages']
+  env: ['NIGHTLY=$_NIGHTLY']
 
 # Converter.
 - name: 'gcr.io/cloud-builders/gcloud'
diff --git a/scripts/run-build.sh b/scripts/run-build.sh
index c5dabdf7595..118b9693830 100755
--- a/scripts/run-build.sh
+++ b/scripts/run-build.sh
@@ -17,6 +17,6 @@
 set -e
 
 DIR=$1
-if test -f "$DIR/run-ci"; then
+if [[ -f "$DIR/run-ci" || "$NIGHTLY" = true ]]; then
   gcloud builds submit . --config=$DIR/cloudbuild.yml
 fi
diff --git a/tfjs-core/scripts/test-ci.sh b/tfjs-core/scripts/test-ci.sh
index 67f51d33b5d..4f32b82f01b 100755
--- a/tfjs-core/scripts/test-ci.sh
+++ b/tfjs-core/scripts/test-ci.sh
@@ -20,21 +20,26 @@ yarn lint
 # Test in node (headless environment).
 yarn test-node-ci
 
-# Run the first karma separately so it can download the BrowserStack binary
-# without conflicting with others.
-yarn run-browserstack --browsers=bs_safari_mac,bs_ios_11 --testEnv webgl1 --flags '{"WEBGL_CPU_FORWARD": false, "WEBGL_SIZE_UPLOAD_UNIFORM": 0}'
+if [ "$NIGHTLY" = true ]
+then
+  # Run the first karma separately so it can download the BrowserStack binary
+  # without conflicting with others.
+  yarn run-browserstack --browsers=bs_safari_mac,bs_ios_11 --testEnv webgl1 --flags '{"WEBGL_CPU_FORWARD": false, "WEBGL_SIZE_UPLOAD_UNIFORM": 0}'
 
-# Run the rest of the karma tests in parallel. These runs will reuse the
-# already downloaded binary.
-npm-run-all -p -c --aggregate-output \
-  "run-browserstack --browsers=bs_safari_mac,bs_ios_11,bs_android_9 --flags '{\"HAS_WEBGL\": false}' --testEnv cpu" \
-  "run-browserstack --browsers=bs_firefox_mac,bs_chrome_mac" \
-  "run-browserstack --browsers=bs_chrome_mac,win_10_chrome,bs_android_9 --testEnv webgl2 --flags '{\"WEBGL_CPU_FORWARD\": false, \"WEBGL_SIZE_UPLOAD_UNIFORM\": 0}'" \
-  "run-browserstack --browsers=bs_chrome_mac --testEnv webgl2 --flags '{\"WEBGL_PACK\": false}'" \
+  # Run the rest of the karma tests in parallel. These runs will reuse the
+  # already downloaded binary.
+  npm-run-all -p -c --aggregate-output \
+    "run-browserstack --browsers=bs_safari_mac,bs_ios_11,bs_android_9 --flags '{\"HAS_WEBGL\": false}' --testEnv cpu" \
+    "run-browserstack --browsers=bs_firefox_mac,bs_chrome_mac" \
+    "run-browserstack --browsers=bs_chrome_mac,win_10_chrome,bs_android_9 --testEnv webgl2 --flags '{\"WEBGL_CPU_FORWARD\": false, \"WEBGL_SIZE_UPLOAD_UNIFORM\": 0}'" \
+    "run-browserstack --browsers=bs_chrome_mac --testEnv webgl2 --flags '{\"WEBGL_PACK\": false}'" \
 
-### The next section tests TF.js in a webworker.
-# Make a dist/tf-core.min.js file to be imported by the web worker.
-yarn rollup -c --ci
-# Safari doesn't have offscreen canvas so test cpu in a webworker.
-# Chrome has offscreen canvas, so test webgl in a webworker.
-yarn test-webworker --browsers=bs_safari_mac,bs_chrome_mac
+  ### The next section tests TF.js in a webworker.
+  # Make a dist/tf-core.min.js file to be imported by the web worker.
+  yarn rollup -c --ci
+  # Safari doesn't have offscreen canvas so test cpu in a webworker.
+  # Chrome has offscreen canvas, so test webgl in a webworker.
+  yarn test-webworker --browsers=bs_safari_mac,bs_chrome_mac
+else
+  yarn run-browserstack --browsers=bs_chrome_mac
+fi