diff --git a/dune/fem-dg/misc/streams.hh b/dune/fem-dg/misc/streams.hh
index 1056cf1973e1d6e93a23c235109df76dc1394884..498705bcdf8dc394f564d9da565c6fe4f3aa4c3b 100644
--- a/dune/fem-dg/misc/streams.hh
+++ b/dune/fem-dg/misc/streams.hh
@@ -3,7 +3,7 @@
 
 #if HAVE_SIONLIB
 #if USE_SIONLIB
-#warning "using SIONlib streams for output"
+#warning "using SIONlib streams for I/O"
 
 #include <dune/fem/io/streams/sionlibstreams.hh>