diff --git a/.gitignore b/.gitignore
index ee9c849031..6e545f741d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -45,6 +45,7 @@ Manuals/*/*Guide.pdf
 *.sf
 *.bf
 *.s3d
+*.s3dd
 *.q
 *.sz
 *.smv