diff --git a/.gitignore b/.gitignore
index d097598..ac81c9a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,4 +16,5 @@ src/coreSig.ml
 src/extSigs.ml
 config.log
 Makefile
-META
\ No newline at end of file
+META
+_opam