diff --git a/layout/base/nsDocumentViewer.cpp b/layout/base/nsDocumentViewer.cpp
index 6b24d7048653..7f4ca54d2dbb 100644
--- a/layout/base/nsDocumentViewer.cpp
+++ b/layout/base/nsDocumentViewer.cpp
@@ -3201,6 +3201,27 @@ NS_IMETHODIMP DocumentViewerImpl::GetBidiSupport(PRUint8* aSupport)
   return NS_OK;
 }
 
+NS_IMETHODIMP DocumentViewerImpl::SetBidiCharacterSet(PRUint8 aCharacterSet)
+{
+  PRUint32 bidiOptions;
+
+  GetBidiOptions(&bidiOptions);
+  SET_BIDI_OPTION_CHARACTERSET(bidiOptions, aCharacterSet);
+  SetBidiOptions(bidiOptions);
+  return NS_OK;
+}
+
+NS_IMETHODIMP DocumentViewerImpl::GetBidiCharacterSet(PRUint8* aCharacterSet)
+{
+  PRUint32 bidiOptions;
+
+  if (aCharacterSet) {
+    GetBidiOptions(&bidiOptions);
+    *aCharacterSet = GET_BIDI_OPTION_CHARACTERSET(bidiOptions);
+  }
+  return NS_OK;
+}
+
 NS_IMETHODIMP DocumentViewerImpl::SetBidiOptions(PRUint32 aBidiOptions)
 {
   if (mPresContext) {
diff --git a/layout/base/nsPresContext.cpp b/layout/base/nsPresContext.cpp
index 6cbca726f83d..5065e858e7f4 100644
--- a/layout/base/nsPresContext.cpp
+++ b/layout/base/nsPresContext.cpp
@@ -764,6 +764,11 @@ nsPresContext::GetUserPreferences()
                                GET_BIDI_OPTION_SUPPORT(bidiOptions));
   SET_BIDI_OPTION_SUPPORT(bidiOptions, prefInt);
 
+  prefInt =
+    nsContentUtils::GetIntPref(IBMBIDI_CHARSET_STR,
+                               GET_BIDI_OPTION_CHARACTERSET(bidiOptions));
+  SET_BIDI_OPTION_CHARACTERSET(bidiOptions, prefInt);
+
   // We don't need to force reflow: either we are initializing a new
   // prescontext or we are being called from UpdateAfterPreferencesChanged()
   // which triggers a reflow anyway.