diff --git a/src/doc/uuid_io.h b/src/doc/uuid_io.h
index 7ce0a0f2d..c5b0a4900 100644
--- a/src/doc/uuid_io.h
+++ b/src/doc/uuid_io.h
@@ -10,7 +10,7 @@
 
 #include "base/uuid.h"
 
-#include <iostream>
+#include <iosfwd>
 
 namespace doc {