diff --git a/mozilla/layout/base/nsPresShell.cpp b/mozilla/layout/base/nsPresShell.cpp
index 7f17748005f..9a3d576938a 100644
--- a/mozilla/layout/base/nsPresShell.cpp
+++ b/mozilla/layout/base/nsPresShell.cpp
@@ -161,7 +161,7 @@ static PRBool gDoAsyncReflowAfterDocLoad = PR_FALSE;
 // 200 bytes
 class FrameArena {
 public:
-  FrameArena(PRUint32 aArenaSize = 2048);
+  FrameArena(PRUint32 aArenaSize = 4096);
   ~FrameArena();
 
   // Memory management functions
diff --git a/mozilla/layout/html/base/src/nsPresShell.cpp b/mozilla/layout/html/base/src/nsPresShell.cpp
index 7f17748005f..9a3d576938a 100644
--- a/mozilla/layout/html/base/src/nsPresShell.cpp
+++ b/mozilla/layout/html/base/src/nsPresShell.cpp
@@ -161,7 +161,7 @@ static PRBool gDoAsyncReflowAfterDocLoad = PR_FALSE;
 // 200 bytes
 class FrameArena {
 public:
-  FrameArena(PRUint32 aArenaSize = 2048);
+  FrameArena(PRUint32 aArenaSize = 4096);
   ~FrameArena();
 
   // Memory management functions