diff --git a/layout/reftests/w3c-css/submitted/flexbox/flexbox-align-self-stretch-vert-1.html b/layout/reftests/w3c-css/submitted/flexbox/flexbox-align-self-stretch-vert-1.html
index 97500acfd7cc..44e5d32362d4 100644
--- a/layout/reftests/w3c-css/submitted/flexbox/flexbox-align-self-stretch-vert-1.html
+++ b/layout/reftests/w3c-css/submitted/flexbox/flexbox-align-self-stretch-vert-1.html
@@ -7,7 +7,7 @@
 <head>
   <title>CSS Test: Testing the sizing of a stretched horizontal flex container in a vertical flex container</title>
   <link rel="author" title="Daniel Holbert" href="mailto:dholbert@mozilla.com">
-  <link rel="help" href="http://dev.w3.org/csswg/css-flexbox/#layout-algorithm">
+  <link rel="help" href="http://www.w3.org/TR/css3-flexbox/#layout-algorithm">
   <link rel="match" href="flexbox-align-self-stretch-vert-1-ref.html">
   <meta name="assert" content="If a stretched flex item's main size is influenced by its cross size, and the flex container has a definite cross size, then the item's cross size should be resolved early so that it can be used when determining the item's main size">
   <meta name="assert" content="http://dev.w3.org/csswg/css-flexbox/issues-cr-2012#issue-23">
diff --git a/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-horiz-1a.html b/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-horiz-1a.html
index 0288b05663cc..f33ef86033b3 100644
--- a/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-horiz-1a.html
+++ b/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-horiz-1a.html
@@ -7,7 +7,7 @@
 <head>
   <title>CSS Test: Testing page-break-before in horizontal multi-line flex containers</title>
   <link rel="author" title="Daniel Holbert" href="mailto:dholbert@mozilla.com">
-  <link rel="help" href="http://dev.w3.org/csswg/css-flexbox/#algo-line-break">
+  <link rel="help" href="http://www.w3.org/TR/css3-flexbox/#algo-line-break">
   <link rel="match" href="flexbox-break-request-horiz-1-ref.html">
   <meta charset="utf-8">
   <style>
diff --git a/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-horiz-1b.html b/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-horiz-1b.html
index 5e08ab7f4cf6..683c29834d21 100644
--- a/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-horiz-1b.html
+++ b/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-horiz-1b.html
@@ -7,7 +7,7 @@
 <head>
   <title>CSS Test: Testing page-break-after in horizontal multi-line flex containers</title>
   <link rel="author" title="Daniel Holbert" href="mailto:dholbert@mozilla.com">
-  <link rel="help" href="http://dev.w3.org/csswg/css-flexbox/#algo-line-break">
+  <link rel="help" href="http://www.w3.org/TR/css3-flexbox/#algo-line-break">
   <link rel="match" href="flexbox-break-request-horiz-1-ref.html">
   <meta charset="utf-8">
   <style>
diff --git a/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-horiz-2a.html b/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-horiz-2a.html
index cf8df2aa1605..5ed9728e3410 100644
--- a/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-horiz-2a.html
+++ b/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-horiz-2a.html
@@ -7,7 +7,7 @@
 <head>
   <title>CSS Test: Testing page-break-before in horizontal single-line flex containers (should have no effect)</title>
   <link rel="author" title="Daniel Holbert" href="mailto:dholbert@mozilla.com">
-  <link rel="help" href="http://dev.w3.org/csswg/css-flexbox/#algo-line-break">
+  <link rel="help" href="http://www.w3.org/TR/css3-flexbox/#algo-line-break">
   <link rel="match" href="flexbox-break-request-horiz-2-ref.html">
   <meta charset="utf-8">
   <style>
diff --git a/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-horiz-2b.html b/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-horiz-2b.html
index cce055bb6f1c..083c1dfd51bf 100644
--- a/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-horiz-2b.html
+++ b/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-horiz-2b.html
@@ -7,7 +7,7 @@
 <head>
   <title>CSS Test: Testing page-break-after in horizontal single-line flex containers (should have no effect)</title>
   <link rel="author" title="Daniel Holbert" href="mailto:dholbert@mozilla.com">
-  <link rel="help" href="http://dev.w3.org/csswg/css-flexbox/#algo-line-break">
+  <link rel="help" href="http://www.w3.org/TR/css3-flexbox/#algo-line-break">
   <link rel="match" href="flexbox-break-request-horiz-2-ref.html">
   <meta charset="utf-8">
   <style>
diff --git a/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-vert-1a.html b/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-vert-1a.html
index f590ce6844bc..38c49d9d6c36 100644
--- a/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-vert-1a.html
+++ b/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-vert-1a.html
@@ -7,7 +7,7 @@
 <head>
   <title>CSS Test: Testing page-break-before in vertical multi-line flex containers</title>
   <link rel="author" title="Daniel Holbert" href="mailto:dholbert@mozilla.com">
-  <link rel="help" href="http://dev.w3.org/csswg/css-flexbox/#algo-line-break">
+  <link rel="help" href="http://www.w3.org/TR/css3-flexbox/#algo-line-break">
   <link rel="match" href="flexbox-break-request-vert-1-ref.html">
   <meta charset="utf-8">
   <style>
diff --git a/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-vert-1b.html b/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-vert-1b.html
index 69b7ea7b3378..89cf139c206b 100644
--- a/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-vert-1b.html
+++ b/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-vert-1b.html
@@ -7,7 +7,7 @@
 <head>
   <title>CSS Test: Testing page-break-after in vertical multi-line flex containers</title>
   <link rel="author" title="Daniel Holbert" href="mailto:dholbert@mozilla.com">
-  <link rel="help" href="http://dev.w3.org/csswg/css-flexbox/#algo-line-break">
+  <link rel="help" href="http://www.w3.org/TR/css3-flexbox/#algo-line-break">
   <link rel="match" href="flexbox-break-request-vert-1-ref.html">
   <meta charset="utf-8">
   <style>
diff --git a/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-vert-2a.html b/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-vert-2a.html
index 59b52ea4f08e..030a00834d9c 100644
--- a/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-vert-2a.html
+++ b/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-vert-2a.html
@@ -7,7 +7,7 @@
 <head>
   <title>CSS Test: Testing page-break-before in vertical single-line flex containers (should have no effect)</title>
   <link rel="author" title="Daniel Holbert" href="mailto:dholbert@mozilla.com">
-  <link rel="help" href="http://dev.w3.org/csswg/css-flexbox/#algo-line-break">
+  <link rel="help" href="http://www.w3.org/TR/css3-flexbox/#algo-line-break">
   <link rel="match" href="flexbox-break-request-vert-2-ref.html">
   <meta charset="utf-8">
   <style>
diff --git a/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-vert-2b.html b/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-vert-2b.html
index b6ae2c042c19..31936c699efc 100644
--- a/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-vert-2b.html
+++ b/layout/reftests/w3c-css/submitted/flexbox/flexbox-break-request-vert-2b.html
@@ -7,7 +7,7 @@
 <head>
   <title>CSS Test: Testing page-break-after in vertical single-line flex containers (should have no effect)</title>
   <link rel="author" title="Daniel Holbert" href="mailto:dholbert@mozilla.com">
-  <link rel="help" href="http://dev.w3.org/csswg/css-flexbox/#algo-line-break">
+  <link rel="help" href="http://www.w3.org/TR/css3-flexbox/#algo-line-break">
   <link rel="match" href="flexbox-break-request-vert-2-ref.html">
   <meta charset="utf-8">
   <style>
diff --git a/layout/reftests/w3c-css/submitted/flexbox/flexbox-flex-wrap-horiz-1.html b/layout/reftests/w3c-css/submitted/flexbox/flexbox-flex-wrap-horiz-1.html
index a7eed85366fb..2560ecdf23c8 100644
--- a/layout/reftests/w3c-css/submitted/flexbox/flexbox-flex-wrap-horiz-1.html
+++ b/layout/reftests/w3c-css/submitted/flexbox/flexbox-flex-wrap-horiz-1.html
@@ -7,7 +7,7 @@
 <head>
   <title>CSS Test: Testing flex-wrap in horizontal flex containers</title>
   <link rel="author" title="Daniel Holbert" href="mailto:dholbert@mozilla.com">
-  <link rel="help" href="http://dev.w3.org/csswg/css-flexbox/#flex-wrap-property">
+  <link rel="help" href="http://www.w3.org/TR/css3-flexbox/#flex-wrap-property">
   <link rel="match" href="flexbox-flex-wrap-horiz-1-ref.html">
   <meta charset="utf-8">
   <style>
diff --git a/layout/reftests/w3c-css/submitted/flexbox/flexbox-flex-wrap-horiz-2.html b/layout/reftests/w3c-css/submitted/flexbox/flexbox-flex-wrap-horiz-2.html
index 6d4bb8bef28d..f37366862152 100644
--- a/layout/reftests/w3c-css/submitted/flexbox/flexbox-flex-wrap-horiz-2.html
+++ b/layout/reftests/w3c-css/submitted/flexbox/flexbox-flex-wrap-horiz-2.html
@@ -7,7 +7,7 @@
 <head>
   <title>CSS Test: Ensure that min-width is honored for horizontal multi-line flex containers</title>
   <link rel="author" title="Daniel Holbert" href="mailto:dholbert@mozilla.com">
-  <link rel="help" href="http://dev.w3.org/csswg/css-flexbox/#flex-wrap-property">
+  <link rel="help" href="http://www.w3.org/TR/css3-flexbox/#flex-wrap-property">
   <link rel="match" href="flexbox-flex-wrap-horiz-2-ref.html">
   <meta charset="utf-8">
   <style>
diff --git a/layout/reftests/w3c-css/submitted/flexbox/flexbox-flex-wrap-vert-1.html b/layout/reftests/w3c-css/submitted/flexbox/flexbox-flex-wrap-vert-1.html
index b33e3ba04d71..a71f0af359e4 100644
--- a/layout/reftests/w3c-css/submitted/flexbox/flexbox-flex-wrap-vert-1.html
+++ b/layout/reftests/w3c-css/submitted/flexbox/flexbox-flex-wrap-vert-1.html
@@ -7,7 +7,7 @@
 <head>
   <title>CSS Test: Testing flex-wrap in vertical flex containers</title>
   <link rel="author" title="Daniel Holbert" href="mailto:dholbert@mozilla.com">
-  <link rel="help" href="http://dev.w3.org/csswg/css-flexbox/#flex-wrap-property">
+  <link rel="help" href="http://www.w3.org/TR/css3-flexbox/#flex-wrap-property">
   <link rel="match" href="flexbox-flex-wrap-vert-1-ref.html">
   <meta charset="utf-8">
   <style>
diff --git a/layout/reftests/w3c-css/submitted/flexbox/flexbox-flex-wrap-vert-2.html b/layout/reftests/w3c-css/submitted/flexbox/flexbox-flex-wrap-vert-2.html
index 0cfc2711a1ec..ce17cef685f7 100644
--- a/layout/reftests/w3c-css/submitted/flexbox/flexbox-flex-wrap-vert-2.html
+++ b/layout/reftests/w3c-css/submitted/flexbox/flexbox-flex-wrap-vert-2.html
@@ -7,7 +7,7 @@
 <head>
   <title>CSS Test: Ensure that min-height is honored for vertical multi-line flex containers</title>
   <link rel="author" title="Daniel Holbert" href="mailto:dholbert@mozilla.com">
-  <link rel="help" href="http://dev.w3.org/csswg/css-flexbox/#flex-wrap-property">
+  <link rel="help" href="http://www.w3.org/TR/css3-flexbox/#flex-wrap-property">
   <link rel="match" href="flexbox-flex-wrap-vert-2-ref.html">
   <meta charset="utf-8">
   <style>
