diff --git a/src/runtime/tree.c b/src/runtime/tree.c
index 5b43bede..1a67ecda 100644
--- a/src/runtime/tree.c
+++ b/src/runtime/tree.c
@@ -79,6 +79,7 @@ TSTree *ts_tree_make_copy(TSTree *self) {
     return NULL;
 
   *result = *self;
+  result->ref_count = 1;
   return result;
 }