diff --git a/libguile/frames.c b/libguile/frames.c
index 0bb40579c..87afaec3d 100644
--- a/libguile/frames.c
+++ b/libguile/frames.c
@@ -41,6 +41,7 @@
 
 #include "frames.h"
 
+#include <stdio.h>
 
 SCM
 scm_c_make_frame (enum scm_vm_frame_kind kind, const struct scm_frame *frame)
@@ -272,6 +273,11 @@ scm_frame_local_ref (SCM frame, SCM index, SCM representation)
       switch (repr)
         {
           case STACK_ITEM_SCM:
+            fprintf(stderr, "i: %u  SCM: %p\n", (unsigned) i, (void*)item->as_u64);
+            if (item->as_u64 == 0x07)
+              return SCM_EOF_VAL;
+            if (item->as_u64 == 0x09)
+              return SCM_EOF_VAL;
             return item->as_scm;
           case STACK_ITEM_F64:
             return scm_from_double (item->as_f64);