diff --git a/mozilla/layout/forms/nsTextControlFrame.cpp b/mozilla/layout/forms/nsTextControlFrame.cpp
index 990af34c9bd..d5b890bfe4e 100644
--- a/mozilla/layout/forms/nsTextControlFrame.cpp
+++ b/mozilla/layout/forms/nsTextControlFrame.cpp
@@ -1428,7 +1428,8 @@ nsTextControlFrame::CalculateSizeStandard(nsPresContext*       aPresContext,
   fontMet->GetMaxAdvance(charMaxAdvance);
 
   // Set the width equal to the width in characters
-  aDesiredSize.width = GetCols() * charWidth;
+  PRInt32 cols = GetCols();
+  aDesiredSize.width = cols * charWidth;
 
   // To better match IE, take the maximum character width(in twips) and remove
   // 4 pixels add this on as additional padding(internalPadding). But only do
@@ -1456,6 +1457,17 @@ nsTextControlFrame::CalculateSizeStandard(nsPresContext*       aPresContext,
     }
   }
 
+  // Increment width with cols * letter-spacing.
+  {
+    const nsStyleCoord& lsCoord = GetStyleText()->mLetterSpacing;
+    if (eStyleUnit_Coord == lsCoord.GetUnit()) {
+      nscoord letterSpacing = lsCoord.GetCoordValue();
+      if (letterSpacing != 0) {
+        aDesiredSize.width += cols * letterSpacing;
+      }
+    }
+  }
+
   // Set the height equal to total number of rows (times the height of each
   // line, of course)
   aDesiredSize.height = fontHeight * GetRows();
diff --git a/mozilla/layout/html/forms/src/nsTextControlFrame.cpp b/mozilla/layout/html/forms/src/nsTextControlFrame.cpp
index 990af34c9bd..d5b890bfe4e 100644
--- a/mozilla/layout/html/forms/src/nsTextControlFrame.cpp
+++ b/mozilla/layout/html/forms/src/nsTextControlFrame.cpp
@@ -1428,7 +1428,8 @@ nsTextControlFrame::CalculateSizeStandard(nsPresContext*       aPresContext,
   fontMet->GetMaxAdvance(charMaxAdvance);
 
   // Set the width equal to the width in characters
-  aDesiredSize.width = GetCols() * charWidth;
+  PRInt32 cols = GetCols();
+  aDesiredSize.width = cols * charWidth;
 
   // To better match IE, take the maximum character width(in twips) and remove
   // 4 pixels add this on as additional padding(internalPadding). But only do
@@ -1456,6 +1457,17 @@ nsTextControlFrame::CalculateSizeStandard(nsPresContext*       aPresContext,
     }
   }
 
+  // Increment width with cols * letter-spacing.
+  {
+    const nsStyleCoord& lsCoord = GetStyleText()->mLetterSpacing;
+    if (eStyleUnit_Coord == lsCoord.GetUnit()) {
+      nscoord letterSpacing = lsCoord.GetCoordValue();
+      if (letterSpacing != 0) {
+        aDesiredSize.width += cols * letterSpacing;
+      }
+    }
+  }
+
   // Set the height equal to total number of rows (times the height of each
   // line, of course)
   aDesiredSize.height = fontHeight * GetRows();