diff --git a/taglib/toolkit/tvariant.h b/taglib/toolkit/tvariant.h
index a8408e54..26c67ec3 100644
--- a/taglib/toolkit/tvariant.h
+++ b/taglib/toolkit/tvariant.h
@@ -26,7 +26,7 @@
 #ifndef TAGLIB_VARIANT_H
 #define TAGLIB_VARIANT_H
 
-#include <iosfwd>
+#include <sstream>
 
 #include "tlist.h"
 #include "tmap.h"