From b8f590def887de27471780d50a2dd5b158ceb21b Mon Sep 17 00:00:00 2001
From: Andrew Johnson <andrew.johnson@arjohnsonau.com>
Date: Fri, 17 Jan 2025 21:44:02 +0800
Subject: [PATCH] cos header

---
 stan/math/fwd/fun/sin.hpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/stan/math/fwd/fun/sin.hpp b/stan/math/fwd/fun/sin.hpp
index a208ff190be..81971f9714e 100644
--- a/stan/math/fwd/fun/sin.hpp
+++ b/stan/math/fwd/fun/sin.hpp
@@ -6,6 +6,7 @@
 #include <stan/math/fwd/fun/sinh.hpp>
 #include <stan/math/fwd/fun/cos.hpp>
 #include <stan/math/prim/fun/sin.hpp>
+#include <stan/math/prim/fun/cos.hpp>
 #include <cmath>
 #include <complex>