diff --git a/src/plugins/region/dune b/src/plugins/region/dune
index 7b9540c6c488a82fdf40cbe82aaf6889d1195138..f4f00f77e3abbaac66d5fb72b9b59018d629a236 100644
--- a/src/plugins/region/dune
+++ b/src/plugins/region/dune
@@ -38,10 +38,8 @@
  (public_name frama-c-region.core)
  (flags -open Frama_c_kernel :standard -w -9)
  (libraries frama-c.kernel frama-c-server.core unionFind)
- (instrumentation
-  (backend landmarks))
- (instrumentation
-  (backend bisect_ppx)))
+ (instrumentation (backend landmarks))
+ (instrumentation (backend bisect_ppx)))
 
 (plugin
  (optional)