diff --git a/bin/dune b/bin/dune
index 6f805b1..5e8d2a4 100644
--- a/bin/dune
+++ b/bin/dune
@@ -1,4 +1,10 @@
 (executable
  (public_name mlox)
  (libraries Lox)
- (name main))
+ (name main)
+ (modes exe byte))
+
+(env
+ (release
+  (ocamlopt_flags
+   (:standard -O3))))
diff --git a/lib/dune b/lib/dune
index 52c8dad..b021fd5 100644
--- a/lib/dune
+++ b/lib/dune
@@ -2,3 +2,9 @@
  (name Lox)
  (preprocess
   (pps ppx_deriving.show)))
+
+(env
+ (dev)
+ (release
+  (ocamlopt_flags
+   (:standard -O3))))