diff --git a/gc.c b/gc.c
index f7bc528f..1cfc1759 100644
--- a/gc.c
+++ b/gc.c
@@ -793,6 +793,11 @@ void gc_wait_handshake()
 /////////////////////////////////////////////
 // GC Collection cycle
 
+//TODO: create function to print globals, ideally want names and the mark flag.
+//then call before/after tracing to see if we can catch a global not being marked.
+//want to rule out an issue here, since we have seen globals that were corrupted (IE, appears they were collected)
+void debug_dump_globals();
+
 // Main collector function
 void gc_collector()
 {
@@ -812,19 +817,20 @@ void gc_collector()
   while(!ATOMIC_SET_IF_EQ(&gc_color_mark, old_mark, old_clear)){}
 printf("DEBUG - swap clear %d / mark %d\n", gc_color_clear, gc_color_mark);
   gc_handshake(STATUS_SYNC1);
-printf("DEBUG - after handshake sync 1\n");
+//printf("DEBUG - after handshake sync 1\n");
   //mark : 
   gc_handshake(STATUS_SYNC2);
-printf("DEBUG - after handshake sync 2\n");
+//printf("DEBUG - after handshake sync 2\n");
   gc_stage = STAGE_TRACING;
   gc_post_handshake(STATUS_ASYNC);
-printf("DEBUG - after post_handshake aync\n");
+//printf("DEBUG - after post_handshake aync\n");
   gc_mark_globals();
   gc_wait_handshake();
-printf("DEBUG - after wait_handshake aync\n");
+//printf("DEBUG - after wait_handshake aync\n");
   //trace : 
   gc_collector_trace();
-printf("DEBUG - after trace\n");
+//printf("DEBUG - after trace\n");
+debug_dump_globals();
   gc_stage = STAGE_SWEEPING;
   //
   //sweep : 
diff --git a/runtime.c b/runtime.c
index 4804d8b2..4f7c18d5 100644
--- a/runtime.c
+++ b/runtime.c
@@ -206,6 +206,27 @@ void add_global(object *glo) {
   // this is more expedient
   global_table = mcons(mcvar(glo), global_table);
 }
+
+void debug_dump_globals()
+{
+  list l = global_table;
+  for(; !nullp(l); l = cdr(l)){
+   cvar_type *c = (cvar_type *)car(l);
+   //gc_mark(h, *(c->pvar)); // Mark actual object the global points to
+   printf("DEBUG %p ", c->pvar);
+   if (*c->pvar){
+     printf("mark = %d ", mark(*c->pvar));
+     if (mark(*c->pvar) == gc_color_red) {
+       printf("obj = ");
+       Cyc_display(*c->pvar, stdout);
+     }
+     printf("\n");
+   } else { 
+     printf(" is NULL\n");
+   }
+  }
+}
+
 /* END Global table */
 
 /* Mutation table
@@ -2417,7 +2438,10 @@ void gc_mark_globals()
     list l = global_table;
     for(; !nullp(l); l = cdr(l)){
      cvar_type *c = (cvar_type *)car(l);
-     gc_mark_black(*(c->pvar)); // Mark actual object the global points to
+     object glo =  *(c->pvar);
+     if (!nullp(glo)) {
+       gc_mark_black(glo); // Mark actual object the global points to
+     }
     }
   }
 }