diff --git a/.gitattributes b/.gitattributes
index ef61a9a..386929a 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1,4 +1,4 @@
-*.cow filter=lfs diff=lfs merge=lfs -text
+*.cow filter=lfs diff=lfs merge=lfs -text lockable
 *.mis filter=lfs diff=lfs merge=lfs -text
 *.gam filter=lfs diff=lfs merge=lfs -text
 fam/** filter=lfs diff=lfs merge=lfs -text