2 files changed, 7 insertions, 3 deletions
diff --git a/src/crypto/dh/CMakeLists.txt b/src/crypto/dh/CMakeLists.txt
index 9e487d5..d0c1da7 100644
--- a/src/crypto/dh/CMakeLists.txt
+++ b/src/crypto/dh/CMakeLists.txt
@@ -16,6 +16,8 @@ add_executable(
   dh_test
 
   dh_test.cc
+
+  $<TARGET_OBJECTS:test_support>
 )
 
 target_link_libraries(dh_test crypto)
diff --git a/src/crypto/dh/dh.c b/src/crypto/dh/dh.c
index ab7ed8b..96b85f3 100644
--- a/src/crypto/dh/dh.c
+++ b/src/crypto/dh/dh.c
@@ -116,7 +116,7 @@ void DH_free(DH *dh) {
     return;
   }
 
-  if (CRYPTO_add(&dh->references, -1, CRYPTO_LOCK_DH) > 0) {
+  if (!CRYPTO_refcount_dec_and_test_zero(&dh->references)) {
     return;
   }
 
@@ -164,8 +164,10 @@ int DH_compute_key(unsigned char *out, const BIGNUM *peers_key, DH *dh) {
 
 int DH_size(const DH *dh) { return BN_num_bytes(dh->p); }
 
-int DH_up_ref(DH *r) {
-  CRYPTO_add(&r->references, 1, CRYPTO_LOCK_DH);
+unsigned DH_num_bits(const DH *dh) { return BN_num_bits(dh->p); }
+
+int DH_up_ref(DH *dh) {
+  CRYPTO_refcount_inc(&dh->references);
   return 1;
 }