diff --git a/opam/opam b/opam/opam
index 7b2c44a9fa950c7f74182a16dd6bf4f04e6cd759..5f39c63fc90a835be65bdd935954671337f19488 100644
--- a/opam/opam
+++ b/opam/opam
@@ -100,7 +100,7 @@ depends: [
 ]
 
 depopts: [
-  "coq" { build }
+  "coq" # cannot use {build}: Frama-C must be recompiled when Coq changes
   "why3" { build }
   "why3-coq" { build }
   "mlgmpidl" { build }