1 files changed, 4 insertions, 0 deletions

diff --git a/src/alloc.c b/src/alloc.c
index d22e71bd1a8..15bfbbbb1b7 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -6220,6 +6220,8 @@ mark_object (Lisp_Object arg)
           break;
         CHECK_ALLOCATED_AND_LIVE (live_symbol_p);
         ptr->gcmarkbit = 1;
+        /* Attempt to catch bogus objects.  */
+        eassert (valid_lisp_object_p (ptr->function) >= 1);
         mark_object (ptr->function);
         mark_object (ptr->plist);
         switch (ptr->redirect)
@@ -6640,6 +6642,8 @@ sweep_symbols (void)
             {
               ++num_used;
               sym->s.gcmarkbit = 0;
+              /* Attempt to catch bogus objects.  */
+              eassert (valid_lisp_object_p (sym->s.function) >= 1);
             }
         }