diff --git a/Geomview/include/CGAL/IO/Geomview_stream.h b/Geomview/include/CGAL/IO/Geomview_stream.h
index b9d3ba957c0..e3b3f222fe1 100644
--- a/Geomview/include/CGAL/IO/Geomview_stream.h
+++ b/Geomview/include/CGAL/IO/Geomview_stream.h
@@ -31,6 +31,8 @@
 #include <CGAL/IO/Color.h>
 #include <CGAL/IO/Ostream_iterator.h>
 
+#include <CGAL/export/CGAL.h>
+
 #include <map>
 #include <vector>
 #include <utility>
@@ -40,7 +42,7 @@
 
 namespace CGAL {
 
-class Geomview_stream {
+class CGAL_EXPORT Geomview_stream {
 public:
     Geomview_stream(const Bbox_3 &bbox = Bbox_3(0,0,0, 1,1,1),
 		    const char *machine = NULL,
@@ -549,10 +551,10 @@ operator<<(Geomview_stream &gv, const Line_3<R> &r)
 }
 #endif
 
-Geomview_stream&
+CGAL_EXPORT Geomview_stream&
 operator<<(Geomview_stream &gv, const Bbox_2 &bbox);
 
-Geomview_stream&
+CGAL_EXPORT Geomview_stream&
 operator<<(Geomview_stream &gv, const Bbox_3 &bbox);
 
 #if defined CGAL_POINT_3_H && !defined CGAL_GV_IN_POINT_3_H
diff --git a/Stream_support/include/CGAL/IO/File_header_OFF.h b/Stream_support/include/CGAL/IO/File_header_OFF.h
index 179c3a81343..726e3aa3b9a 100644
--- a/Stream_support/include/CGAL/IO/File_header_OFF.h
+++ b/Stream_support/include/CGAL/IO/File_header_OFF.h
@@ -110,10 +110,10 @@ public:
 };
 
 // Write header.
-std::ostream& operator<<( std::ostream& out, const File_header_OFF& h);
+CGAL_EXPORT std::ostream& operator<<( std::ostream& out, const File_header_OFF& h);
 
 // Scan header. Marks streams badbit if not in SKEL format nor in OFF.
-std::istream& operator>>( std::istream& in, File_header_OFF& h);
+CGAL_EXPORT std::istream& operator>>( std::istream& in, File_header_OFF& h);
 
 } //namespace CGAL
 #endif // CGAL_IO_FILE_HEADER_OFF_H //