diff --git a/mozilla/xpcom/tests/TestObserverService.cpp b/mozilla/xpcom/tests/TestObserverService.cpp
index 4fef2a8de42..600167dccb6 100644
--- a/mozilla/xpcom/tests/TestObserverService.cpp
+++ b/mozilla/xpcom/tests/TestObserverService.cpp
@@ -29,6 +29,7 @@
 #include "nsString.h"
 #include "prprf.h"
 #include <iostream.h>
+#include <iomanip.h>   // needed for libstdc++-v3
 #include "nsWeakReference.h"
 
 static nsIObserverService *anObserverService = NULL;
diff --git a/mozilla/xpcom/tools/registry/regxpcom.cpp b/mozilla/xpcom/tools/registry/regxpcom.cpp
index a57f3b7cca6..c67bb6382f2 100644
--- a/mozilla/xpcom/tools/registry/regxpcom.cpp
+++ b/mozilla/xpcom/tools/registry/regxpcom.cpp
@@ -22,6 +22,7 @@
  */
 
 #include <iostream.h>
+#include <iomanip.h>   // needed for libstdc++-v3
 
 #ifdef XP_MAC
 #include "macstdlibextras.h"