diff --git a/include/openssl/stack.h b/include/openssl/stack.h
index 100b1db..23b9d89 100644
--- a/include/openssl/stack.h
+++ b/include/openssl/stack.h
@@ -337,27 +337,28 @@
 typedef OPENSSL_STACK _STACK;
 
 // The following functions call the corresponding |OPENSSL_sk_*| function.
-OPENSSL_EXPORT OPENSSL_STACK *sk_new_null(void);
-OPENSSL_EXPORT size_t sk_num(const OPENSSL_STACK *sk);
-OPENSSL_EXPORT void *sk_value(const OPENSSL_STACK *sk, size_t i);
-OPENSSL_EXPORT void sk_free(OPENSSL_STACK *sk);
-OPENSSL_EXPORT size_t sk_push(OPENSSL_STACK *sk, void *p);
-OPENSSL_EXPORT void *sk_pop(OPENSSL_STACK *sk);
+OPENSSL_EXPORT OPENSSL_DEPRECATED OPENSSL_STACK *sk_new_null(void);
+OPENSSL_EXPORT OPENSSL_DEPRECATED size_t sk_num(const OPENSSL_STACK *sk);
+OPENSSL_EXPORT OPENSSL_DEPRECATED void *sk_value(const OPENSSL_STACK *sk,
+                                                 size_t i);
+OPENSSL_EXPORT OPENSSL_DEPRECATED void sk_free(OPENSSL_STACK *sk);
+OPENSSL_EXPORT OPENSSL_DEPRECATED size_t sk_push(OPENSSL_STACK *sk, void *p);
+OPENSSL_EXPORT OPENSSL_DEPRECATED void *sk_pop(OPENSSL_STACK *sk);
 
 // sk_pop_free_ex calls |OPENSSL_sk_pop_free_ex|.
 //
 // TODO(b/291994116): Remove this.
-OPENSSL_EXPORT void sk_pop_free_ex(OPENSSL_STACK *sk,
-                                   OPENSSL_sk_call_free_func call_free_func,
-                                   OPENSSL_sk_free_func free_func);
+OPENSSL_EXPORT OPENSSL_DEPRECATED void sk_pop_free_ex(
+    OPENSSL_STACK *sk, OPENSSL_sk_call_free_func call_free_func,
+    OPENSSL_sk_free_func free_func);
 
 // sk_pop_free behaves like |OPENSSL_sk_pop_free_ex| but performs an invalid
 // function pointer cast. It exists because some existing callers called
 // |sk_pop_free| directly.
 //
 // TODO(davidben): Migrate callers to bssl::UniquePtr and remove this.
-OPENSSL_EXPORT void sk_pop_free(OPENSSL_STACK *sk,
-                                OPENSSL_sk_free_func free_func);
+OPENSSL_EXPORT OPENSSL_DEPRECATED void sk_pop_free(
+    OPENSSL_STACK *sk, OPENSSL_sk_free_func free_func);
 
 
 #if !defined(BORINGSSL_NO_CXX)