diff --git a/library/.gitignore b/library/.gitignore
index d9a3e979b..1e9d24c88 100644
--- a/library/.gitignore
+++ b/library/.gitignore
@@ -1,2 +1,4 @@
-.lean_options
-TAGS
\ No newline at end of file
+TAGS
+build.ninja
+.ninja_deps
+.ninja_log