diff --git a/src/util/user.c b/src/util/user.c
@@ -48,7 +48,7 @@ static int user_usage_new(UserUsage **usagep, User *user, uid_t uid) {
                 return error_origin(-ENOMEM);
 
         usage->n_refs = REF_INIT;
-        usage->user = user;
+        usage->user = user_ref(user);
         usage->uid = uid;
         usage->user_node = (CRBNode)C_RBNODE_INIT(usage->user_node);
 
@@ -64,6 +64,7 @@ static void user_usage_free(_Atomic unsigned long *n_refs, void *userdata) {
                 c_assert(!usage->slots[i]);
 
         user_usage_unlink(usage);
+        user_unref(usage->user);
         free(usage);
 }
 
@@ -388,7 +389,7 @@ int user_registry_init(UserRegistry *registry,
 
         registry->log = log;
         registry->n_slots = n_slots;
-        memcpy(registry->maxima, maxima, n_slots * sizeof(*registry->maxima));
+        c_memcpy(registry->maxima, maxima, n_slots * sizeof(*registry->maxima));
 
         return 0;
 }

diff --git a/test/dbus/test-fdstream.c b/test/dbus/test-fdstream.c
@@ -74,7 +74,7 @@ static void test_fd_stream_send(Connection *c, unsigned int unix_fds, unsigned i
         if (n_fds > 0) {
                 int fds[n_fds];
 
-                memset(fds, 0, sizeof(fds));
+                c_memset(fds, 0, sizeof(fds));
                 r = fdlist_new_with_fds(&m->fds, fds, n_fds);
                 c_assert(!r);
         }

diff --git a/test/dbus/util-message.c b/test/dbus/util-message.c
@@ -43,7 +43,7 @@ static void test_message_append(void **buf, size_t *n_buf, const void *data, siz
         p = realloc(*buf, *n_buf + n_data);
         c_assert(p);
 
-        memcpy(p + *n_buf, data, n_data);
+        c_memcpy(p + *n_buf, data, n_data);
 
         *buf = p;
         *n_buf += n_data;