diff --git a/src/interp/dune b/src/interp/dune
index 5b05cc7..5f4d91b 100644
--- a/src/interp/dune
+++ b/src/interp/dune
@@ -1,3 +1,3 @@
 (library
  (name interp)
- (libraries p smtlib parse check reduce))
+ (libraries p smtlib parse check reduce unix))