diff --git a/library.c b/library.c
index 91d6ffb..3a596c0 100644
--- a/library.c
+++ b/library.c
@@ -179,11 +179,6 @@ static int redis_sock_append_auth(RedisSock *redis_sock, smart_string *str) {
     return 1;
 }
 
-PHP_REDIS_API void
-redis_sock_copy_auth(RedisSock *dst, RedisSock *src) {
-    redis_sock_set_auth(dst, src->user, src->pass);
-}
-
 PHP_REDIS_API void
 redis_sock_set_auth(RedisSock *redis_sock, zend_string *user, zend_string *pass)
 {
diff --git a/library.h b/library.h
index 293012c..21d523b 100644
--- a/library.h
+++ b/library.h
@@ -77,7 +77,6 @@ PHP_REDIS_API int redis_sock_auth(RedisSock *redis_sock);
 PHP_REDIS_API char *redis_sock_auth_cmd(RedisSock *redis_sock, int *cmdlen);
 PHP_REDIS_API void redis_sock_set_auth(RedisSock *redis_sock, zend_string *user, zend_string *pass);
 PHP_REDIS_API void redis_sock_set_auth_zval(RedisSock *redis_sock, zval *zv);
-PHP_REDIS_API void redis_sock_copy_auth(RedisSock *dst, RedisSock *src);
 PHP_REDIS_API void redis_sock_free_auth(RedisSock *redis_sock);
 PHP_REDIS_API int redis_sock_disconnect(RedisSock *redis_sock, int force);
 PHP_REDIS_API zval *redis_sock_read_multibulk_reply_zval(INTERNAL_FUNCTION_PARAMETERS, RedisSock *redis_sock, zval *z_tab);