diff --git a/mozilla/docshell/base/nsDocShell.cpp b/mozilla/docshell/base/nsDocShell.cpp
index cc28c9ed9c5..a84a9ce2673 100644
--- a/mozilla/docshell/base/nsDocShell.cpp
+++ b/mozilla/docshell/base/nsDocShell.cpp
@@ -1931,6 +1931,7 @@ nsDocShell::AddChild(nsIDocShellTreeItem * aChild)
     // Do some docShell Specific stuff.
     nsXPIDLString defaultCharset;
     nsXPIDLString forceCharset;
+    float textZoom = 1.0;
     NS_ENSURE_TRUE(mContentViewer, NS_ERROR_FAILURE);
 
     nsCOMPtr<nsIMarkupDocumentViewer> muDV =
@@ -1942,6 +1943,9 @@ nsDocShell::AddChild(nsIDocShellTreeItem * aChild)
         NS_ENSURE_SUCCESS(muDV->
                           GetForceCharacterSet(getter_Copies(forceCharset)),
                           NS_ERROR_FAILURE);
+        NS_ENSURE_SUCCESS(muDV->
+                          GetTextZoom(&textZoom),
+                          NS_ERROR_FAILURE);
     }
     nsCOMPtr<nsIContentViewer> childCV;
     NS_ENSURE_SUCCESS(childAsDocShell->
@@ -1955,6 +1959,8 @@ nsDocShell::AddChild(nsIDocShellTreeItem * aChild)
                               NS_ERROR_FAILURE);
             NS_ENSURE_SUCCESS(childmuDV->SetForceCharacterSet(forceCharset),
                               NS_ERROR_FAILURE);
+            NS_ENSURE_SUCCESS(childmuDV->SetTextZoom(textZoom),
+                              NS_ERROR_FAILURE);
         }
     }