diff --git a/samples/opengl/isosurf/.cvsignore b/samples/opengl/isosurf/.cvsignore
index b9116d02e5..03fb5e4a3d 100644
--- a/samples/opengl/isosurf/.cvsignore
+++ b/samples/opengl/isosurf/.cvsignore
@@ -4,3 +4,4 @@ isosurfM*Data
 *Classic?Release*
 *Carbon?Debug*
 *Carbon?Release*
+isosurf.dat
\ No newline at end of file