diff --git a/layout/generic/nsFrame.cpp b/layout/generic/nsFrame.cpp
index 5e7a24b55d6..90bcc0d0b95 100644
--- a/layout/generic/nsFrame.cpp
+++ b/layout/generic/nsFrame.cpp
@@ -3184,7 +3184,8 @@ nsIFrame::InlineMinWidthData::ForceBreak(nsIRenderingContext *aRenderingContext)
 }
 
 void
-nsIFrame::InlineMinWidthData::OptionallyBreak(nsIRenderingContext *aRenderingContext)
+nsIFrame::InlineMinWidthData::OptionallyBreak(nsIRenderingContext *aRenderingContext,
+                                              nscoord aHyphenWidth)
 {
   trailingTextFrame = nsnull;
 
@@ -3193,8 +3194,9 @@ nsIFrame::InlineMinWidthData::OptionallyBreak(nsIRenderingContext *aRenderingCon
   // text-indent or negative margin), don't break.  Otherwise, do the
   // same as ForceBreak.  it doesn't really matter when we accumulate
   // floats.
-  if (currentLine < 0 || atStartOfLine)
+  if (currentLine + aHyphenWidth < 0 || atStartOfLine)
     return;
+  currentLine += aHyphenWidth;
   ForceBreak(aRenderingContext);
 }
 
diff --git a/layout/generic/nsIFrame.h b/layout/generic/nsIFrame.h
index 68ce2e9eef1..5e1cc76d4c9 100644
--- a/layout/generic/nsIFrame.h
+++ b/layout/generic/nsIFrame.h
@@ -1465,7 +1465,11 @@ public:
     // optional breaks to prevent min-width from ending up bigger than
     // pref-width.
     void ForceBreak(nsIRenderingContext *aRenderingContext);
-    void OptionallyBreak(nsIRenderingContext *aRenderingContext);
+
+    // If the break here is actually taken, aHyphenWidth must be added to the
+    // width of the current line.
+    void OptionallyBreak(nsIRenderingContext *aRenderingContext,
+                         nscoord aHyphenWidth = 0);
 
     // The last text frame processed so far in the current line, when
     // the last characters in that text frame are relevant for line
diff --git a/layout/generic/nsTextFrameThebes.cpp b/layout/generic/nsTextFrameThebes.cpp
index 6ad2de7fb98..19dd117717a 100644
--- a/layout/generic/nsTextFrameThebes.cpp
+++ b/layout/generic/nsTextFrameThebes.cpp
@@ -6072,8 +6072,19 @@ nsTextFrame::AddInlineMinWidthForFlow(nsIRenderingContext *aRenderingContext,
   // OK since we can't really handle tabs for intrinsic sizing anyway.
   const nsStyleText* textStyle = GetStyleText();
   const nsTextFragment* frag = mContent->GetText();
+
+  // If we're hyphenating, the PropertyProvider needs the actual length;
+  // otherwise we can just pass PR_INT32_MAX to mean "all the text"
+  PRInt32 len = PR_INT32_MAX;
+  PRBool hyphenating =
+    (mTextRun->GetFlags() & gfxTextRunFactory::TEXT_ENABLE_HYPHEN_BREAKS) != 0;
+  if (hyphenating) {
+    gfxSkipCharsIterator tmp(iter);
+    len =
+      tmp.ConvertSkippedToOriginal(flowEndInTextRun) - iter.GetOriginalOffset();
+  }
   PropertyProvider provider(mTextRun, textStyle, frag, this,
-                            iter, PR_INT32_MAX, nsnull, 0);
+                            iter, len, nsnull, 0);
 
   PRBool collapseWhitespace = !textStyle->WhiteSpaceIsSignificant();
   PRBool preformatNewlines = textStyle->NewlineIsSignificant();
@@ -6082,7 +6093,16 @@ nsTextFrame::AddInlineMinWidthForFlow(nsIRenderingContext *aRenderingContext,
   PRUint32 start =
     FindStartAfterSkippingWhitespace(&provider, aData, textStyle, &iter, flowEndInTextRun);
 
-  // XXX Should we consider hyphenation here?
+  nsAutoTArray<PRPackedBool,BIG_TEXT_NODE_SIZE> hyphBuffer;
+  PRPackedBool *hyphBreakBefore = nsnull;
+  if (hyphenating) {
+    hyphBreakBefore = hyphBuffer.AppendElements(flowEndInTextRun - start);
+    if (hyphBreakBefore) {
+      provider.GetHyphenationBreaks(start, flowEndInTextRun - start,
+                                    hyphBreakBefore);
+    }
+  }
+
   for (PRUint32 i = start, wordStart = start; i <= flowEndInTextRun; ++i) {
     PRBool preformattedNewline = PR_FALSE;
     PRBool preformattedTab = PR_FALSE;
@@ -6092,8 +6112,11 @@ nsTextFrame::AddInlineMinWidthForFlow(nsIRenderingContext *aRenderingContext,
       // starts?
       preformattedNewline = preformatNewlines && mTextRun->GetChar(i) == '\n';
       preformattedTab = preformatTabs && mTextRun->GetChar(i) == '\t';
-      if (!mTextRun->CanBreakLineBefore(i) && !preformattedNewline &&
-          !preformattedTab) {
+      if (!mTextRun->CanBreakLineBefore(i) &&
+          !preformattedNewline &&
+          !preformattedTab &&
+          (!hyphBreakBefore || !hyphBreakBefore[i - start]))
+      {
         // we can't break here (and it's not the end of the flow)
         continue;
       }
@@ -6135,6 +6158,8 @@ nsTextFrame::AddInlineMinWidthForFlow(nsIRenderingContext *aRenderingContext,
          (mTextRun->GetFlags() & nsTextFrameUtils::TEXT_HAS_TRAILING_BREAK))) {
       if (preformattedNewline) {
         aData->ForceBreak(aRenderingContext);
+      } else if (hyphBreakBefore && hyphBreakBefore[i - start]) {
+        aData->OptionallyBreak(aRenderingContext, provider.GetHyphenWidth());
       } else {
         aData->OptionallyBreak(aRenderingContext);
       }