diff --git a/layout/generic/nsFirstLetterFrame.cpp b/layout/generic/nsFirstLetterFrame.cpp
index 699c58387e6a..a23a12408655 100644
--- a/layout/generic/nsFirstLetterFrame.cpp
+++ b/layout/generic/nsFirstLetterFrame.cpp
@@ -226,6 +226,15 @@ nsFirstLetterFrame::Reflow(nsPresContext*          aPresContext,
     aMetrics.SetSize(wm, convertedSize);
     aMetrics.SetBlockStartAscent(kidMetrics.BlockStartAscent() +
                                  bp.BStart(wm));
+
+    // Ensure that the overflow rect contains the child textframe's
+    // overflow rect.
+    // Note that if this is floating, the overline/underline drawable
+    // area is in the overflow rect of the child textframe.
+    aMetrics.UnionOverflowAreasWithDesiredBounds();
+    ConsiderChildOverflow(aMetrics.mOverflowAreas, kid);
+
+    FinishAndStoreOverflow(&aMetrics);
   }
   else {
     // Pretend we are a span and reflow the child frame
@@ -247,12 +256,6 @@ nsFirstLetterFrame::Reflow(nsPresContext*          aPresContext,
     nsLayoutUtils::SetBSizeFromFontMetrics(this, aMetrics, bp, lineWM, wm);
   }
 
-  // Ensure that the overflow rect contains the child textframe's overflow rect.
-  // Note that if this is floating, the overline/underline drawable area is in
-  // the overflow rect of the child textframe.
-  aMetrics.UnionOverflowAreasWithDesiredBounds();
-  ConsiderChildOverflow(aMetrics.mOverflowAreas, kid);
-
   if (!NS_INLINE_IS_BREAK_BEFORE(aReflowStatus)) {
     // Create a continuation or remove existing continuations based on
     // the reflow completion status.
@@ -287,8 +290,6 @@ nsFirstLetterFrame::Reflow(nsPresContext*          aPresContext,
     }
   }
 
-  FinishAndStoreOverflow(&aMetrics);
-
   NS_FRAME_SET_TRUNCATION(aReflowStatus, aReflowState, aMetrics);
 }
 
diff --git a/layout/reftests/first-letter/overflow-float-nooverflow-ref.html b/layout/reftests/first-letter/overflow-float-nooverflow-ref.html
new file mode 100644
index 000000000000..fad9f0e63d40
--- /dev/null
+++ b/layout/reftests/first-letter/overflow-float-nooverflow-ref.html
@@ -0,0 +1,14 @@
+<title>::first-letter and overflow</title>
+<style>
+
+div {
+  height: 8em; width: 5em;
+  padding: 3px;
+  background: yellow; color: black;
+  line-height: 1.0;
+}
+div::first-letter { font-size: 1.2em; float: left; }
+
+</style>
+
+<div>Hello world, testing, testing, testing, testing</div>
diff --git a/layout/reftests/first-letter/overflow-float-nooverflow.html b/layout/reftests/first-letter/overflow-float-nooverflow.html
new file mode 100644
index 000000000000..ff9020344346
--- /dev/null
+++ b/layout/reftests/first-letter/overflow-float-nooverflow.html
@@ -0,0 +1,15 @@
+<title>::first-letter and overflow</title>
+<style>
+
+div {
+  height: 8em; width: 5em;
+  padding: 3px;
+  background: yellow; color: black;
+  overflow: auto;
+  line-height: 1.0;
+}
+div::first-letter { font-size: 1.2em; float: left; }
+
+</style>
+
+<div>Hello world, testing, testing, testing, testing</div>
diff --git a/layout/reftests/first-letter/overflow-float-overflow-notref.html b/layout/reftests/first-letter/overflow-float-overflow-notref.html
new file mode 100644
index 000000000000..7eb0bca37a76
--- /dev/null
+++ b/layout/reftests/first-letter/overflow-float-overflow-notref.html
@@ -0,0 +1,14 @@
+<title>::first-letter and overflow</title>
+<style>
+
+div {
+  height: 3em; width: 8em;
+  padding: 3px;
+  background: yellow; color: black;
+  line-height: 1.0;
+}
+div::first-letter { font-size: 4em; float: left; }
+
+</style>
+
+<div>Hello</div>
diff --git a/layout/reftests/first-letter/overflow-float-overflow.html b/layout/reftests/first-letter/overflow-float-overflow.html
new file mode 100644
index 000000000000..0d0d1ee933bb
--- /dev/null
+++ b/layout/reftests/first-letter/overflow-float-overflow.html
@@ -0,0 +1,15 @@
+<title>::first-letter and overflow</title>
+<style>
+
+div {
+  height: 3em; width: 8em;
+  padding: 3px;
+  background: yellow; color: black;
+  overflow: auto;
+  line-height: 1.0;
+}
+div::first-letter { font-size: 4em; float: left; }
+
+</style>
+
+<div>Hello</div>
diff --git a/layout/reftests/first-letter/overflow-inline-nooverflow-ref.html b/layout/reftests/first-letter/overflow-inline-nooverflow-ref.html
new file mode 100644
index 000000000000..856c3a8a07be
--- /dev/null
+++ b/layout/reftests/first-letter/overflow-inline-nooverflow-ref.html
@@ -0,0 +1,14 @@
+<title>::first-letter and overflow</title>
+<style>
+
+div {
+  height: 8em; width: 5em;
+  padding: 3px;
+  background: yellow; color: black;
+  line-height: 1.0;
+}
+div::first-letter { font-size: 1.2em }
+
+</style>
+
+<div>Hello world, testing, testing, testing, testing</div>
diff --git a/layout/reftests/first-letter/overflow-inline-nooverflow.html b/layout/reftests/first-letter/overflow-inline-nooverflow.html
new file mode 100644
index 000000000000..7a48a3c4c0d0
--- /dev/null
+++ b/layout/reftests/first-letter/overflow-inline-nooverflow.html
@@ -0,0 +1,15 @@
+<title>::first-letter and overflow</title>
+<style>
+
+div {
+  height: 8em; width: 5em;
+  padding: 3px;
+  background: yellow; color: black;
+  overflow: auto;
+  line-height: 1.0;
+}
+div::first-letter { font-size: 1.2em }
+
+</style>
+
+<div>Hello world, testing, testing, testing, testing</div>
diff --git a/layout/reftests/first-letter/overflow-inline-overflow-notref.html b/layout/reftests/first-letter/overflow-inline-overflow-notref.html
new file mode 100644
index 000000000000..772d835266ff
--- /dev/null
+++ b/layout/reftests/first-letter/overflow-inline-overflow-notref.html
@@ -0,0 +1,14 @@
+<title>::first-letter and overflow</title>
+<style>
+
+div {
+  height: 3em; width: 8em;
+  padding: 3px;
+  background: yellow; color: black;
+  line-height: 1.0;
+}
+div::first-letter { font-size: 4em }
+
+</style>
+
+<div>Hello</div>
diff --git a/layout/reftests/first-letter/overflow-inline-overflow-ref.html b/layout/reftests/first-letter/overflow-inline-overflow-ref.html
new file mode 100644
index 000000000000..196168c804ae
--- /dev/null
+++ b/layout/reftests/first-letter/overflow-inline-overflow-ref.html
@@ -0,0 +1,15 @@
+<title>::first-letter and overflow</title>
+<style>
+
+div {
+  height: 3em; width: 8em;
+  padding: 3px;
+  background: yellow; color: black;
+  overflow: auto;
+  line-height: 1.0;
+}
+span { font-size: 4em }
+
+</style>
+
+<div><span>H</span>ello</div>
diff --git a/layout/reftests/first-letter/overflow-inline-overflow.html b/layout/reftests/first-letter/overflow-inline-overflow.html
new file mode 100644
index 000000000000..a7b95c1e9b0f
--- /dev/null
+++ b/layout/reftests/first-letter/overflow-inline-overflow.html
@@ -0,0 +1,15 @@
+<title>::first-letter and overflow</title>
+<style>
+
+div {
+  height: 3em; width: 8em;
+  padding: 3px;
+  background: yellow; color: black;
+  overflow: auto;
+  line-height: 1.0;
+}
+div::first-letter { font-size: 4em }
+
+</style>
+
+<div>Hello</div>
diff --git a/layout/reftests/first-letter/reftest.list b/layout/reftests/first-letter/reftest.list
index defd14ebeccd..62247aaa8918 100644
--- a/layout/reftests/first-letter/reftest.list
+++ b/layout/reftests/first-letter/reftest.list
@@ -67,3 +67,8 @@ fails-if(winWidget||cocoaWidget) == 617869-1.html 617869-1-ref.html
 fails-if(gtk2Widget) random-if(winWidget&&!d2d) == font-text-styles-floater.html font-text-styles-floater-ref.html # bug 992846
 == inline-height-empty.html inline-height-empty-ref.html
 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