diff --git a/src/posix/dune b/src/posix/dune
index 9cfb691..d6f26d1 100644
--- a/src/posix/dune
+++ b/src/posix/dune
@@ -1,7 +1,8 @@
 (library
  (name nanoev_posix)
  (public_name nanoev-posix)
- (enabled_if (= %{os_type} "Unix"))
+ (enabled_if
+  (= %{os_type} "Unix"))
  (synopsis "posix backend (poll/ppoll+mtime)")
  (private_modules heap)
  (libraries threads nanoev unix iomux mtime mtime.clock.os))