--- a/layout/base/ServoRestyleManager.cpp
+++ b/layout/base/ServoRestyleManager.cpp
@@ -63,23 +63,26 @@ ExpectedOwnerForChild(const nsIFrame& aF
     return parent->IsViewportFrame() ?
       nullptr : FirstContinuationOrPartOfIBSplit(parent);
   }
 
   if (aFrame.IsBulletFrame()) {
     return parent;
   }
 
-  if (aFrame.IsLineFrame()) {
+  if (aFrame.IsLineFrame() || aFrame.IsLetterFrame()) {
     // A ::first-line always ends up here via its block, which is therefore the
     // right expected owner.  That block can be an
     // anonymous box.  For example, we could have a ::first-line on a columnated
     // block; the blockframe is the column-content anonymous box in that case.
     // So we don't want to end up in the code below, which steps out of anon
     // boxes.  Just return the parent of the line frame, which is the block.
+    //
+    // Ditto for ::first-letter. A first-letter always arrives here via its
+    // direct parent.
     return parent;
   }
 
   parent = FirstContinuationOrPartOfIBSplit(parent);
 
   // We've handled already anon boxes and bullet frames, so now we're looking at
   // a frame of a DOM element or pseudo. Hop through anon and line-boxes
   // generated by our DOM parent, and go find the owner frame for it.
@@ -562,27 +565,30 @@ UpdateBackdropIfNeeded(nsIFrame* aFrame,
   nsTArray<nsIFrame*> wrappersToRestyle;
   ServoRestyleState state(aStyleSet, aChangeList, wrappersToRestyle);
   aFrame->UpdateStyleOfOwnedChildFrame(backdropFrame, newContext, state);
 }
 
 static void
 UpdateFirstLetterIfNeeded(nsIFrame* aFrame, ServoRestyleState& aRestyleState)
 {
+  MOZ_ASSERT(!aFrame->IsFrameOfType(nsIFrame::eBlockFrame),
+             "You're probably duplicating work with UpdatePseudoElementStyles!");
   if (!aFrame->HasFirstLetterChild()) {
     return;
   }
 
   // We need to find the block the first-letter is associated with so we can
   // find the right element for the first-letter's style resolution.  Might as
   // well just delegate the whole thing to that block.
-  nsIFrame* block = aFrame;
+  nsIFrame* block = aFrame->GetParent();
   while (!block->IsFrameOfType(nsIFrame::eBlockFrame)) {
     block = block->GetParent();
   }
+
   static_cast<nsBlockFrame*>(block->FirstContinuation())->
     UpdateFirstLetterStyle(aRestyleState);
 }
 
 static void
 UpdateOneAdditionalStyleContext(nsIFrame* aFrame,
                                 uint32_t aIndex,
                                 ServoStyleContext& aOldContext,
@@ -633,22 +639,20 @@ UpdateAdditionalStyleContexts(nsIFrame* 
         aFrame, index++, *oldContext->AsServo(), aRestyleState);
   }
 }
 
 static void
 UpdateFramePseudoElementStyles(nsIFrame* aFrame,
                                ServoRestyleState& aRestyleState)
 {
-  // first-letter needs to be updated before first-line, because first-line can
-  // change the style of the first-letter.
-  UpdateFirstLetterIfNeeded(aFrame, aRestyleState);
-
   if (aFrame->IsFrameOfType(nsIFrame::eBlockFrame)) {
     static_cast<nsBlockFrame*>(aFrame)->UpdatePseudoElementStyles(aRestyleState);
+  } else {
+    UpdateFirstLetterIfNeeded(aFrame, aRestyleState);
   }
 
   UpdateBackdropIfNeeded(
     aFrame, aRestyleState.StyleSet(), aRestyleState.ChangeList());
 }
 
 enum class ServoPostTraversalFlags : uint32_t
 {

--- a/layout/generic/nsBlockFrame.cpp
+++ b/layout/generic/nsBlockFrame.cpp
@@ -7576,16 +7576,22 @@ nsBlockFrame::ResolveBidi()
   }
 
   return nsBidiPresUtils::Resolve(this);
 }
 
 void
 nsBlockFrame::UpdatePseudoElementStyles(ServoRestyleState& aRestyleState)
 {
+  // first-letter needs to be updated before first-line, because first-line can
+  // change the style of the first-letter.
+  if (HasFirstLetterChild()) {
+    UpdateFirstLetterStyle(aRestyleState);
+  }
+
   if (nsBulletFrame* bullet = GetBullet()) {
     CSSPseudoElementType type = bullet->StyleContext()->GetPseudoType();
     RefPtr<nsStyleContext> newBulletStyle =
       ResolveBulletStyle(type, &aRestyleState.StyleSet());
     UpdateStyleOfOwnedChildFrame(bullet, newBulletStyle, aRestyleState);
   }
 
   if (nsIFrame* firstLineFrame = GetFirstLineFrame()) {

new file mode 100644
--- /dev/null
+++ b/layout/reftests/first-letter/1404167-1-ref.html
@@ -0,0 +1,12 @@
+<!doctype html>
+<style>
+text::first-letter {
+  font-size: 3em;
+}
+text {
+  font-size: 15px;
+}
+</style>
+<svg width="500px" height="50px">
+  <text x="0" y="40">The first-letter size should be 45px</text>
+</svg>

new file mode 100644
--- /dev/null
+++ b/layout/reftests/first-letter/1404167-1.html
@@ -0,0 +1,16 @@
+<!doctype html>
+<style>
+text::first-letter {
+  font-size: 3em;
+}
+text {
+  font-size: 10px;
+}
+</style>
+<svg width="500px" height="50px">
+  <text x="0" y="40">The first-letter size should be 45px</text>
+</svg>
+<script>
+  document.body.offsetTop;
+  document.querySelector('text').style.fontSize = "15px";
+</script>

new file mode 100644
--- /dev/null
+++ b/layout/reftests/first-letter/1404167-2-ref.html
@@ -0,0 +1,13 @@
+<!doctype html>
+<style>
+td::first-letter {
+  border: inherit;
+}
+</style>
+<table>
+  <tr>
+    <td style="border: 10px solid green">
+      This text should have a green border on the first letter.
+    </td>
+  </tr>
+</table>

new file mode 100644
--- /dev/null
+++ b/layout/reftests/first-letter/1404167-2.html
@@ -0,0 +1,18 @@
+<!doctype html>
+<style>
+td::first-letter {
+  border: inherit;
+}
+</style>
+<table>
+  <tr>
+    <td style="border: 10px solid red">
+      This text should have a green border on the first letter.
+    </td>
+  </tr>
+</table>
+<script>
+document.body.offsetTop;
+document.querySelector('td').style.borderColor = "green";
+document.body.offsetTop;
+</script>

new file mode 100644
--- /dev/null
+++ b/layout/reftests/first-letter/1404167-3-ref.html
@@ -0,0 +1,9 @@
+<!doctype html>
+<style>
+fieldset::first-letter {
+  border: inherit;
+}
+</style>
+<fieldset style="border: 10px solid green;">
+  This text should have a green border on the first letter.
+</fieldset>

new file mode 100644
--- /dev/null
+++ b/layout/reftests/first-letter/1404167-3.html
@@ -0,0 +1,14 @@
+<!doctype html>
+<style>
+fieldset::first-letter {
+  border: inherit;
+}
+</style>
+<fieldset style="border: 10px solid red;">
+  This text should have a green border on the first letter.
+</fieldset>
+<script>
+document.body.offsetTop;
+document.querySelector('fieldset').style.borderColor = "green";
+document.body.offsetTop;
+</script>

--- a/layout/reftests/first-letter/reftest.list
+++ b/layout/reftests/first-letter/reftest.list
@@ -70,8 +70,11 @@ random-if(gtkWidget) random-if(winWidget
 HTTP(..) == indic-clusters-1.html indic-clusters-1-ref.html
 == overflow-float-nooverflow.html overflow-float-nooverflow-ref.html
 == overflow-float-overflow.html overflow-float-overflow-notref.html
 == overflow-inline-nooverflow.html overflow-inline-nooverflow-ref.html
 != overflow-inline-overflow.html overflow-inline-overflow-notref.html
 == overflow-inline-overflow.html overflow-inline-overflow-ref.html
 
 == 1385656.html 1385656-ref.html
+== 1404167-1.html 1404167-1-ref.html
+== 1404167-2.html 1404167-2-ref.html
+== 1404167-3.html 1404167-3-ref.html