diff --git a/src/gc.c b/src/gc.c
index 951a66ac..cf3bd75b 100644
--- a/src/gc.c
+++ b/src/gc.c
@@ -157,6 +157,7 @@ static void
 gc_mark_phase(pic_state *pic)
 {
   pic_value *stack;
+  pic_callinfo *ci;
   struct pic_env *env;
   int i;
 
@@ -165,6 +166,11 @@ gc_mark_phase(pic_state *pic)
     gc_mark(pic, *stack);
   }
 
+  /* callinfo */
+  for (ci = pic->cibase; ci != pic->ci; ++ci) {
+    gc_mark_object(pic, (struct pic_object *)ci->proc);
+  }
+
   /* arena */
   for (i = 0; i < pic->arena_idx; ++i) {
     gc_mark_object(pic, pic->arena[i]);