diff --git a/include/vision.h b/include/vision.h
index 988496a31..c37cedb92 100644
--- a/include/vision.h
+++ b/include/vision.h
@@ -1,4 +1,4 @@
-/* NetHack 3.7	vision.h	$NHDT-Date: 1596498568 2020/08/03 23:49:28 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.13 $ */
+/* NetHack 3.7	vision.h	$NHDT-Date: 1666478832 2022/10/22 22:47:12 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.15 $ */
 /* Copyright (c) Dean Luick, with acknowledgements to Dave Cohrs, 1990. */
 /* NetHack may be freely redistributed.  See license for details.	*/
 
@@ -21,9 +21,9 @@
  *  couldsee()	- Returns true if the hero has a clear line of sight to
  *		  the location.
  */
-#define cansee(x, y) (g.viz_array[y][x] & IN_SIGHT)
-#define couldsee(x, y) (g.viz_array[y][x] & COULD_SEE)
-#define templit(x, y) (g.viz_array[y][x] & TEMP_LIT)
+#define cansee(x, y) ((g.viz_array[y][x] & IN_SIGHT) != 0)
+#define couldsee(x, y) ((g.viz_array[y][x] & COULD_SEE) != 0)
+#define templit(x, y) ((g.viz_array[y][x] & TEMP_LIT) != 0)
 
 /*
  *  The following assume the monster is not blind.