diff --git a/aio/aio-builds-setup/scripts/test.sh b/aio/aio-builds-setup/scripts/test.sh
index 84a1b83e7e..06a9fb76b1 100755
--- a/aio/aio-builds-setup/scripts/test.sh
+++ b/aio/aio-builds-setup/scripts/test.sh
@@ -5,7 +5,8 @@ set -eux -o pipefail
 source "`dirname $0`/_env.sh"
 
 # Test `scripts-js/`
-cd "$SCRIPTS_JS_DIR"
-yarn install
-yarn test
-cd -
+(
+  cd "$SCRIPTS_JS_DIR"
+  yarn install
+  yarn test
+)
diff --git a/aio/aio-builds-setup/scripts/travis-preverify-pr.sh b/aio/aio-builds-setup/scripts/travis-preverify-pr.sh
index f75796a200..e67dff3a30 100755
--- a/aio/aio-builds-setup/scripts/travis-preverify-pr.sh
+++ b/aio/aio-builds-setup/scripts/travis-preverify-pr.sh
@@ -5,10 +5,11 @@ set -eux -o pipefail
 source "`dirname $0`/_env.sh"
 
 # Build `scripts-js/`
-cd "$SCRIPTS_JS_DIR"
-yarn install
-yarn build
-cd -
+(
+  cd "$SCRIPTS_JS_DIR"
+  yarn install
+  yarn build
+)
 
 # Preverify PR
 AIO_GITHUB_ORGANIZATION="angular" \
diff --git a/aio/scripts/deploy-preview.sh b/aio/scripts/deploy-preview.sh
index 21aed29417..a6380f6369 100755
--- a/aio/scripts/deploy-preview.sh
+++ b/aio/scripts/deploy-preview.sh
@@ -15,59 +15,59 @@ readonly PREVERIFY_SCRIPT=aio-builds-setup/scripts/travis-preverify-pr.sh
 readonly skipBuild=$([[ "$1" == "--skip-build" ]] && echo "true" || echo "");
 readonly relevantChangedFilesCount=$(git diff --name-only $TRAVIS_COMMIT_RANGE | grep -P "^(?:aio|packages)/(?!.*[._]spec\.[jt]s$)" | wc -l)
 
-cd "`dirname $0`/.."
+(
+  cd "`dirname $0`/.."
 
-# Do not deploy unless this PR has touched relevant files: `aio/` or `packages/` (except for spec files)
-if [[ $relevantChangedFilesCount -eq 0 ]]; then
-  echo "Skipping deploy because this PR did not touch any relevant files."
-  exit 0
-fi
-
-# Do not deploy unless this PR meets certain preconditions.
-readonly preverifyExitCode=$($PREVERIFY_SCRIPT > /dev/fd/3 && echo 0 || echo $?)
-case $preverifyExitCode in
-  0)
-    # Preconditions met: Deploy
-    ;;
-  1)
-    # An error occurred: Fail the script
-    exit 1
-    ;;
-  2)
-    # Preconditions not met: Skip deploy
-    echo "Skipping deploy because this PR did not meet the preconditions."
+  # Do not deploy unless this PR has touched relevant files: `aio/` or `packages/` (except for spec files)
+  if [[ $relevantChangedFilesCount -eq 0 ]]; then
+    echo "Skipping deploy because this PR did not touch any relevant files."
     exit 0
-    ;;
-  *)
-    # Unexpected exit code: Fail the script
-    echo "Unexpected pre-verification exit code: $preverifyExitCode"
+  fi
+
+  # Do not deploy unless this PR meets certain preconditions.
+  readonly preverifyExitCode=$($PREVERIFY_SCRIPT > /dev/fd/3 && echo 0 || echo $?)
+  case $preverifyExitCode in
+    0)
+      # Preconditions met: Deploy
+      ;;
+    1)
+      # An error occurred: Fail the script
+      exit 1
+      ;;
+    2)
+      # Preconditions not met: Skip deploy
+      echo "Skipping deploy because this PR did not meet the preconditions."
+      exit 0
+      ;;
+    *)
+      # Unexpected exit code: Fail the script
+      echo "Unexpected pre-verification exit code: $preverifyExitCode"
+      exit 1
+      ;;
+  esac
+
+  # Build the app
+  if [ "$skipBuild" != "true" ]; then
+    yarn build
+  fi
+  tar --create --gzip --directory "$INPUT_DIR" --file "$OUTPUT_FILE" .
+
+  # Deploy to staging
+  readonly httpCode=$(
+    curl --include --location --request POST --silent --write-out "\nHTTP_CODE: %{http_code}\n" \
+        --header "Authorization: Token $NGBUILDS_IO_KEY" --data-binary "@$OUTPUT_FILE" "$UPLOAD_URL" \
+    | sed 's/\r\n/\n/' \
+    | tee /dev/fd/3 \
+    | tail -1 \
+    | sed 's/HTTP_CODE: //'
+  )
+
+  # Exit with an error if the request failed.
+  # (Ignore 409 failures, which mean trying to re-deploy for the same PR/SHA.)
+  if [ $httpCode -lt 200 ] || ([ $httpCode -ge 400 ] && [ $httpCode -ne 409 ]); then
     exit 1
-    ;;
-esac
+  fi
 
-# Build the app
-if [ "$skipBuild" != "true" ]; then
-  yarn build
-fi
-tar --create --gzip --directory "$INPUT_DIR" --file "$OUTPUT_FILE" .
-
-# Deploy to staging
-readonly httpCode=$(
-  curl --include --location --request POST --silent --write-out "\nHTTP_CODE: %{http_code}\n" \
-       --header "Authorization: Token $NGBUILDS_IO_KEY" --data-binary "@$OUTPUT_FILE" "$UPLOAD_URL" \
-  | sed 's/\r\n/\n/' \
-  | tee /dev/fd/3 \
-  | tail -1 \
-  | sed 's/HTTP_CODE: //'
+  # Run PWA-score tests
+  yarn test-pwa-score -- "$DEPLOYED_URL" "$MIN_PWA_SCORE"
 )
-
-# Exit with an error if the request failed.
-# (Ignore 409 failures, which mean trying to re-deploy for the same PR/SHA.)
-if [ $httpCode -lt 200 ] || ([ $httpCode -ge 400 ] && [ $httpCode -ne 409 ]); then
-  exit 1
-fi
-
-# Run PWA-score tests
-yarn test-pwa-score -- "$DEPLOYED_URL" "$MIN_PWA_SCORE"
-
-cd -
diff --git a/aio/scripts/deploy-staging.sh b/aio/scripts/deploy-staging.sh
index dcaab1469d..c7e8eea59d 100755
--- a/aio/scripts/deploy-staging.sh
+++ b/aio/scripts/deploy-staging.sh
@@ -7,18 +7,18 @@ set +x -eu -o pipefail
 FIREBASE_PROJECT_ID=aio-staging
 DEPLOYED_URL=https://$FIREBASE_PROJECT_ID.firebaseapp.com
 
-cd "`dirname $0`/.."
+(
+  cd "`dirname $0`/.."
 
-# Build the app
-yarn build
+  # Build the app
+  yarn build
 
-# Deploy to staging
-firebase use "$FIREBASE_PROJECT_ID" --token "$FIREBASE_TOKEN"
-firebase deploy --message "Commit: $TRAVIS_COMMIT" --non-interactive --token "$FIREBASE_TOKEN"
+  # Deploy to staging
+  firebase use "$FIREBASE_PROJECT_ID" --token "$FIREBASE_TOKEN"
+  firebase deploy --message "Commit: $TRAVIS_COMMIT" --non-interactive --token "$FIREBASE_TOKEN"
 
-# Run PWA-score tests
-# TODO(gkalpak): Figure out why this fails and re-enable.
-sleep 10
-yarn test-pwa-score -- "$DEPLOYED_URL" "$MIN_PWA_SCORE" || true
-
-cd -
+  # Run PWA-score tests
+  # TODO(gkalpak): Figure out why this fails and re-enable.
+  sleep 10
+  yarn test-pwa-score -- "$DEPLOYED_URL" "$MIN_PWA_SCORE" || true
+)
diff --git a/build.sh b/build.sh
index dd7aaaca92..04c7f1c877 100755
--- a/build.sh
+++ b/build.sh
@@ -362,38 +362,40 @@ if [[ ${BUILD_ALL} == true && ${TYPECHECK_ALL} == true ]]; then
   travisFoldStart "copy e2e files" "no-xtrace"
     mkdir -p ./dist/all/
 
-    echo "====== Copying files needed for e2e tests ====="
-    cp -r ./modules/playground ./dist/all/
-    cp -r ./modules/playground/favicon.ico ./dist/
-    #rsync -aP ./modules/playground/* ./dist/all/playground/
-    mkdir ./dist/all/playground/vendor
-    cd ./dist/all/playground/vendor
-    ln -s ../../../../node_modules/core-js/client/core.js .
-    ln -s ../../../../node_modules/zone.js/dist/zone.js .
-    ln -s ../../../../node_modules/zone.js/dist/long-stack-trace-zone.js .
-    ln -s ../../../../node_modules/systemjs/dist/system.src.js .
-    ln -s ../../../../node_modules/base64-js .
-    ln -s ../../../../node_modules/reflect-metadata/Reflect.js .
-    ln -s ../../../../node_modules/rxjs .
-    ln -s ../../../../node_modules/angular/angular.js .
-    ln -s ../../../../node_modules/hammerjs/hammer.js .
-    cd -
+    (
+      echo "====== Copying files needed for e2e tests ====="
+      cp -r ./modules/playground ./dist/all/
+      cp -r ./modules/playground/favicon.ico ./dist/
+      #rsync -aP ./modules/playground/* ./dist/all/playground/
+      mkdir ./dist/all/playground/vendor
+      cd ./dist/all/playground/vendor
+      ln -s ../../../../node_modules/core-js/client/core.js .
+      ln -s ../../../../node_modules/zone.js/dist/zone.js .
+      ln -s ../../../../node_modules/zone.js/dist/long-stack-trace-zone.js .
+      ln -s ../../../../node_modules/systemjs/dist/system.src.js .
+      ln -s ../../../../node_modules/base64-js .
+      ln -s ../../../../node_modules/reflect-metadata/Reflect.js .
+      ln -s ../../../../node_modules/rxjs .
+      ln -s ../../../../node_modules/angular/angular.js .
+      ln -s ../../../../node_modules/hammerjs/hammer.js .
+    )
 
-    echo "====== Copying files needed for benchmarks ====="
-    cp -r ./modules/benchmarks ./dist/all/
-    cp -r ./modules/benchmarks/favicon.ico ./dist/
-    mkdir ./dist/all/benchmarks/vendor
-    cd ./dist/all/benchmarks/vendor
-    ln -s ../../../../node_modules/core-js/client/core.js .
-    ln -s ../../../../node_modules/zone.js/dist/zone.js .
-    ln -s ../../../../node_modules/zone.js/dist/long-stack-trace-zone.js .
-    ln -s ../../../../node_modules/systemjs/dist/system.src.js .
-    ln -s ../../../../node_modules/reflect-metadata/Reflect.js .
-    ln -s ../../../../node_modules/rxjs .
-    ln -s ../../../../node_modules/angular/angular.js .
-    ln -s ../../../../bower_components/polymer .
-    ln -s ../../../../node_modules/incremental-dom/dist/incremental-dom-cjs.js
-    cd -
+    (
+      echo "====== Copying files needed for benchmarks ====="
+      cp -r ./modules/benchmarks ./dist/all/
+      cp -r ./modules/benchmarks/favicon.ico ./dist/
+      mkdir ./dist/all/benchmarks/vendor
+      cd ./dist/all/benchmarks/vendor
+      ln -s ../../../../node_modules/core-js/client/core.js .
+      ln -s ../../../../node_modules/zone.js/dist/zone.js .
+      ln -s ../../../../node_modules/zone.js/dist/long-stack-trace-zone.js .
+      ln -s ../../../../node_modules/systemjs/dist/system.src.js .
+      ln -s ../../../../node_modules/reflect-metadata/Reflect.js .
+      ln -s ../../../../node_modules/rxjs .
+      ln -s ../../../../node_modules/angular/angular.js .
+      ln -s ../../../../bower_components/polymer .
+      ln -s ../../../../node_modules/incremental-dom/dist/incremental-dom-cjs.js
+    )
   travisFoldEnd "copy e2e files"
 
   TSCONFIG="packages/tsconfig.json"
diff --git a/scripts/ci/build.sh b/scripts/ci/build.sh
index 9c16c4eb95..ff089d0c20 100755
--- a/scripts/ci/build.sh
+++ b/scripts/ci/build.sh
@@ -40,6 +40,7 @@ travisFoldEnd "tsc a bunch of useless stuff"
 # Build angular.io
 if [[ ${CI_MODE:-} == "aio" ]]; then
   travisFoldStart "build.aio"
+  (
     cd "`dirname $0`/../../aio"
     yarn build
 
@@ -52,7 +53,6 @@ if [[ ${CI_MODE:-} == "aio" ]]; then
         yarn deploy-preview -- --skip-build
       travisFoldEnd "deploy.aio.pr-preview"
     fi
-
-    cd -
+  )
   travisFoldEnd "build.aio"
 fi
diff --git a/tools/code.angularjs.org/publish.sh b/tools/code.angularjs.org/publish.sh
index 580dfbb585..3638616c2e 100755
--- a/tools/code.angularjs.org/publish.sh
+++ b/tools/code.angularjs.org/publish.sh
@@ -30,11 +30,12 @@ function prepare {
 
 
   if [ -d "$REPO_DIR" ]; then
-    cd $REPO_DIR
-    git fetch --update-shallow origin
-    git checkout master
-    git merge --ff-only origin/master
-    cd -
+    (
+      cd $REPO_DIR
+      git fetch --update-shallow origin
+      git checkout master
+      git merge --ff-only origin/master
+    )
   else
     echo "-- Cloning code.angularjs.org into $REPO_DIR"
     git clone git@github.com:angular/code.angularjs.org.git $REPO_DIR --depth=1