1 files changed, 1 insertions, 1 deletions
diff --git a/reclaim.c b/reclaim.c
index fe907fed..b67d6bd4 100644
--- a/reclaim.c
+++ b/reclaim.c
@@ -438,7 +438,7 @@ STATIC void GC_reclaim_block(struct hblk *hbp, word report_if_found)
           /* Here we assume two markers, but this is extremely          */
           /* unlikely to fail spuriously with more.  And if it does, it */
           /* should be looked at.                                       */
-          GC_ASSERT(hhdr -> hb_n_marks <= 2 * (HBLKSIZE/sz + 1) + 16);
+          GC_ASSERT(sz != 0 && hhdr->hb_n_marks <= 2 * (HBLKSIZE/sz + 1) + 16);
 #       else
           GC_ASSERT(sz * hhdr -> hb_n_marks <= HBLKSIZE);
 #       endif