diff --git a/lang/cem/libcc/gen/malloc.c b/lang/cem/libcc/gen/malloc.c
index aa23cd630..4e7d4dd9d 100644
--- a/lang/cem/libcc/gen/malloc.c
+++ b/lang/cem/libcc/gen/malloc.c
@@ -46,7 +46,7 @@ unsigned size;
 
   if ((p = bottom) == 0) {
 	top = bottom = p = sbrk(sizeof(char *));
-	NEXT(top) = 0;
+	NEXT(p) = 0;
   }
   while ((next = NEXT(p)) != 0)
 	if ((vir_bytes) next & BUSY)			/* already in use */