diff --git a/netwerk/streamconv/converters/nsFTPDirListingConv.cpp b/netwerk/streamconv/converters/nsFTPDirListingConv.cpp
index 814a34cf8fe..67640355f0e 100644
--- a/netwerk/streamconv/converters/nsFTPDirListingConv.cpp
+++ b/netwerk/streamconv/converters/nsFTPDirListingConv.cpp
@@ -48,7 +48,7 @@
 #include "nsCOMPtr.h"
 #include "nsEscape.h"
 #include "nsNetUtil.h"
-#include "nsIStringStream.h"
+#include "nsStringStream.h"
 #include "nsILocaleService.h"
 #include "nsIComponentManager.h"
 #include "nsDateTimeFormatCID.h"
diff --git a/netwerk/streamconv/converters/nsGopherDirListingConv.cpp b/netwerk/streamconv/converters/nsGopherDirListingConv.cpp
index a9aeddf335e..821bd76b90c 100644
--- a/netwerk/streamconv/converters/nsGopherDirListingConv.cpp
+++ b/netwerk/streamconv/converters/nsGopherDirListingConv.cpp
@@ -51,7 +51,7 @@
 #include "nsEscape.h"
 #include "nsIStreamListener.h"
 #include "nsIStreamConverter.h"
-#include "nsIStringStream.h"
+#include "nsStringStream.h"
 #include "nsIRequestObserver.h"
 #include "nsNetUtil.h"
 #include "nsMimeTypes.h"
diff --git a/netwerk/streamconv/converters/nsIndexedToHTML.cpp b/netwerk/streamconv/converters/nsIndexedToHTML.cpp
index 8cd0df5c61d..3295a10ceab 100644
--- a/netwerk/streamconv/converters/nsIndexedToHTML.cpp
+++ b/netwerk/streamconv/converters/nsIndexedToHTML.cpp
@@ -39,7 +39,7 @@
 
 #include "nsIndexedToHTML.h"
 #include "nsNetUtil.h"
-#include "nsIStringStream.h"
+#include "nsStringStream.h"
 #include "nsIFileURL.h"
 #include "nsEscape.h"
 #include "nsIDirIndex.h"
diff --git a/netwerk/streamconv/converters/nsTXTToHTMLConv.cpp b/netwerk/streamconv/converters/nsTXTToHTMLConv.cpp
index 85a288da079..5269f9e3a4d 100644
--- a/netwerk/streamconv/converters/nsTXTToHTMLConv.cpp
+++ b/netwerk/streamconv/converters/nsTXTToHTMLConv.cpp
@@ -37,7 +37,7 @@
 
 #include "nsTXTToHTMLConv.h"
 #include "nsNetUtil.h"
-#include "nsIStringStream.h"
+#include "nsStringStream.h"
 #include "nsAutoPtr.h"
 
 #define TOKEN_DELIMITERS NS_LITERAL_STRING("\t\r\n ").get()