diff --git a/.travis.yml b/.travis.yml
index 82fdaab4..cc741fe4 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -54,9 +54,10 @@ install:
 script:
   - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then
       npm test;
+      ./scripts/ci/ensure-staged-sass.sh;
     fi
   - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then
-      ./scripts/build/docker/run-command.sh -r ${TARGET_ARCH} -s ${PWD} -c "xvfb-run --server-args=$XVFB_ARGS npm test";
+      ./scripts/build/docker/run-command.sh -r ${TARGET_ARCH} -s ${PWD} -c "xvfb-run --server-args=$XVFB_ARGS npm test && ./scripts/ci/ensure-staged-sass.sh";
     fi
 
 notifications:
diff --git a/appveyor.yml b/appveyor.yml
index 82aff304..5f0dd480 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -43,6 +43,7 @@ build: off
 test_script:
   - node --version
   - npm --version
+  - bash .\scripts\ci\ensure-staged-sass.sh
   - cmd: npm test
 
 notifications:
diff --git a/scripts/ci/ensure-staged-sass.sh b/scripts/ci/ensure-staged-sass.sh
new file mode 100755
index 00000000..fed53489
--- /dev/null
+++ b/scripts/ci/ensure-staged-sass.sh
@@ -0,0 +1,15 @@
+#!/bin/bash
+
+set -e
+set -u
+
+npm run sass
+
+# From http://stackoverflow.com/a/9393642/1641422
+if [[ -n $(git status -s) ]]; then
+  echo "There are unstaged sass changes. Please commit the result of:" 1>&2
+  echo ""
+  echo "    npm run sass" 1>&2
+  echo ""
+  exit 1
+fi