diff --git a/.gitattributes b/.gitattributes
index 7a5c5bde5..7ed90d7ba 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -8,3 +8,10 @@
 *.jpg binary
 *.hdf5 binary
 *.pdf binary
+
+# ignore files from MSC.Marc in language statistics
+installation/mods_MarcMentat/* linguist-vendored
+src/MarcInclude/*              linguist-vendored
+
+# ignore reference files for tests in language statistics
+python/tests/reference/*       linguist-vendored