diff --git a/theories/base.v b/theories/base.v
index 12e6afd7e9a8018d52d4f16d766d7b9656da106e..3185a0237468a75e6ebe87b6ed9eb24f5259b069 100644
--- a/theories/base.v
+++ b/theories/base.v
@@ -66,7 +66,7 @@ Hint Extern 0 (NoBackTrack _) => constructor; apply _ : typeclass_instances.
as [TCOr (TCAnd P Q) R]: the latter will backtrack to [R] if it fails to
establish [R], i.e. does not have the behavior of a conditional. Furthermore,
note that [TCOr (TCAnd P Q) (TCAnd (TCNot P) R)] would not work; we generally
-would not be able to proof the negation of [P]. *)
+would not be able to prove the negation of [P]. *)
Inductive TCIf (P Q R : Prop) :=
| TCIf_true : P → Q → TCIf P Q R
| TCIf_false : R → TCIf P Q R.