diff --git a/theories/algebra/agree.v b/theories/algebra/agree.v
index 1f6404d4b47ad72a90578a6ccc64639316f63c60..5c13b21c941cde80931195f3b92ef40ea49152e4 100644
--- a/theories/algebra/agree.v
+++ b/theories/algebra/agree.v
@@ -255,6 +255,9 @@ Proof. apply agree_eq. by rewrite /= list_fmap_id. Qed.
Lemma agree_map_compose {A B C} (f : A → B) (g : B → C) (x : agree A) :
agree_map (g ∘ f) x = agree_map g (agree_map f x).
Proof. apply agree_eq. by rewrite /= list_fmap_compose. Qed.
+Lemma agree_map_to_agree {A B} (f : A → B) (x : A) :
+ agree_map f (to_agree x) = to_agree (f x).
+Proof. by apply agree_eq. Qed.
Section agree_map.
Context {A B : ofeT} (f : A → B) `{Hf: NonExpansive f}.