diff --git a/testing/web-platform/tests/css/css-values/vh_not_refreshing_on_chrome.html b/testing/web-platform/tests/css/css-values/vh_not_refreshing_on_chrome.html
index 52a45a114c85..1749986b62c7 100644
--- a/testing/web-platform/tests/css/css-values/vh_not_refreshing_on_chrome.html
+++ b/testing/web-platform/tests/css/css-values/vh_not_refreshing_on_chrome.html
@@ -6,6 +6,7 @@
 	<link rel="author" title="Marc Bourlon" href="mailto:marc@bourlon.com">
 	<link rel="help" href="http://www.w3.org/TR/css3-values/#viewport-relative-lengths">
 	<link rel="match" href="reference/vh_not_refreshing_on_chrome-ref.html">
+	<meta charset="UTF-8">
 	<meta name="assert" content="vh-based dimension doesn't change when the element's other dimension doesn't change.">
 	<!-- This test exhibits a bug for Chrome 19.0.1084.56 / Mac OS X 10.6.8 -->
 	<script src="/common/reftest-wait.js"></script>
diff --git a/testing/web-platform/tests/css/css-values/viewport-relative-lengths-scaled-viewport.html b/testing/web-platform/tests/css/css-values/viewport-relative-lengths-scaled-viewport.html
index a901000394d3..dba2af8fa07b 100644
--- a/testing/web-platform/tests/css/css-values/viewport-relative-lengths-scaled-viewport.html
+++ b/testing/web-platform/tests/css/css-values/viewport-relative-lengths-scaled-viewport.html
@@ -3,6 +3,7 @@
 <!-- Submitted from TestTWF Paris -->
   <head>
     <title>CSS Values and Units Test: Viewport units in scaled viewport</title>
+    <meta charset="UTF-8">
     <meta name="assert" content="viewport relative units scale with viewport.">
     <link rel="author"  title="Emil A Eklund" href="mailto:eae@chromium.org">
     <link rel="help" href="http://www.w3.org/TR/css3-values/#viewport-relative-lengths">
diff --git a/testing/web-platform/tests/css/css-values/viewport-units-css2-001.html b/testing/web-platform/tests/css/css-values/viewport-units-css2-001.html
index f0feb6d99353..c51237dd8a07 100644
--- a/testing/web-platform/tests/css/css-values/viewport-units-css2-001.html
+++ b/testing/web-platform/tests/css/css-values/viewport-units-css2-001.html
@@ -2,6 +2,7 @@
 <html>
 <head>
   <title>CSS Values and Units Test: Checks viewport units against CSS 2.1 properties and the CSSOM</title>
+  <meta charset="UTF-8">
   <meta name="assert" content="Testing what happens when one applies and rereads viewport unit lengths to CSS 2.1 properties that accept length values" />
   <link rel="author" title="Christian Schaefer" href="mailto:schaepp@gmx.de">
   <link rel="help" href="http://www.w3.org/TR/css3-values/#viewport-relative-lengths">
