diff --git a/lib/challenge/preact/preact.go b/lib/challenge/preact/preact.go
index 326992de..43ebe79b 100644
--- a/lib/challenge/preact/preact.go
+++ b/lib/challenge/preact/preact.go
@@ -60,7 +60,7 @@ func (i *impl) Validate(r *http.Request, lg *slog.Logger, in *challenge.Validate
 	wantTime := in.Challenge.IssuedAt.Add(time.Duration(in.Rule.Challenge.Difficulty) * 95 * time.Millisecond)
 
 	if time.Now().Before(wantTime) {
-		return challenge.NewError("validate", "insufficent time", fmt.Errorf("%w: wanted user to wait until at least %s", wantTime.Format(time.RFC3339)))
+		return challenge.NewError("validate", "insufficent time", fmt.Errorf("%s: wanted user to wait until at least %s", wantTime.Format(time.RFC3339)))
 	}
 
 	got := r.FormValue("result")