diff --git a/_CoqProject b/_CoqProject
index 248bdbb..c4b7d33 100644
--- a/_CoqProject
+++ b/_CoqProject
@@ -3,6 +3,7 @@ Map.v
 Var.v
 Sets.v
 Relations.v
+Invariant.v
 Frap.v
 BasicSyntax_template.v
 BasicSyntax.v