diff --git a/.gitattributes b/.gitattributes
index e825e55..41ca663 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1,4 +1,5 @@
 * text=auto !eol
+*.der binary
 *.sln eol=crlf
 *.vcxproj eol=crlf
 *.vcxproj.filters eol=crlf