diff --git a/lib/dune b/lib/dune
index 3b8c040..1eaf41f 100644
--- a/lib/dune
+++ b/lib/dune
@@ -5,7 +5,7 @@
  (flags       (:standard -safe-string))
 
  (c_names     bigstringaf_stubs)
- (c_flags     (-Wall -Wextra -Wpedantic))
+ (c_flags     (:standard -Wall -Wextra -Wpedantic))
 
  (js_of_ocaml (javascript_files runtime.js))
 )