diff --git a/_CoqProject b/_CoqProject
index e2d75403e6d9b1f7354f311cd4931cc912cc4122..b4f5b22a8deb3058cc40a9aebb00518c6b07f78f 100644
--- a/_CoqProject
+++ b/_CoqProject
@@ -1,5 +1,5 @@
 -Q theories iron
--arg -w -arg -notation-overridden,-redundant-canonical-projection,-several-object-files
+-arg -w -arg -notation-overridden,-redundant-canonical-projection,-several-object-files,-undeclared-scope,-convert_concl_no_check
 theories/algebra/ufrac_auth.v
 theories/bi/fracpred.v
 theories/proofmode/fracpred.v
diff --git a/theories/bi/fracpred.v b/theories/bi/fracpred.v
index 5cff46f7a3e1d75ca36d2e32f364fa17c5bfead8..e19b99d3cb8631dd99b05205dbe5af6ac02ec4b0 100644
--- a/theories/bi/fracpred.v
+++ b/theories/bi/fracpred.v
@@ -35,7 +35,7 @@ Section ofe.
 
   Lemma fracPred_ofe_mixin : OfeMixin (fracPred PROP).
   Proof.
-    refine (iso_ofe_mixin (λ P : fracPred _, P : _ -c> _) _ _);
+    refine (iso_ofe_mixin (λ P : fracPred PROP, P : _ -c> _) _ _);
       (split; [by destruct 1|by constructor]).
   Qed.
   Canonical Structure fracPredC : ofeT := OfeT (fracPred PROP) fracPred_ofe_mixin.