diff --git a/openssl-sys/src/lib.rs b/openssl-sys/src/lib.rs
index f12e1f2d..7413be10 100644
--- a/openssl-sys/src/lib.rs
+++ b/openssl-sys/src/lib.rs
@@ -1977,9 +1977,9 @@ extern {
     pub fn d2i_PKCS12(a: *mut *mut PKCS12, pp: *mut *const u8, length: c_long) -> *mut PKCS12;
     pub fn PKCS12_create(pass: *const c_char,
                          friendly_name: *const c_char,
-                         pkey: *const EVP_PKEY,
-                         cert: *const X509,
-                         ca: *const stack_st_X509,
+                         pkey: *mut EVP_PKEY,
+                         cert: *mut X509,
+                         ca: *mut stack_st_X509,
                          nid_key: c_int,
                          nid_cert: c_int,
                          iter: c_int,