1 files changed, 1 insertions, 0 deletions
diff --git a/lex.c b/lex.c
index 2daa0bc..52cd9b8 100644
--- a/lex.c
+++ b/lex.c
@@ -647,6 +647,7 @@ putmac(struct macro *mac)
    uint h, i, n = arraylength(macroht);
    struct macro *slot;
 
+   assert(mac->name);
    i = h = ptrhash(mac->name);
    for (;; ++i) {
       i &= arraylength(macroht) - 1;