1 files changed, 2 insertions, 0 deletions

diff --git a/src/alloc.c b/src/alloc.c
index 3b150797c36..0e48b33882c 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -5863,6 +5863,8 @@ garbage_collect_1 (void *end)
   VECTOR_UNMARK (&buffer_defaults);
   VECTOR_UNMARK (&buffer_local_symbols);
 
+  unmark_main_thread ();
+
   check_cons_list ();
 
   gc_in_progress = 0;