diff --git a/include/file.h b/include/file.h
index 1242a660..640adbc9 100644
--- a/include/file.h
+++ b/include/file.h
@@ -71,18 +71,21 @@ struct empfile {
  * The remaining flags record how the table is being used.
  */
 /* Immutable flags, fixed at compile-time */
+/* Table entries' addresses can't be safely cast to struct emptyped *.  */
+#define EFF_TYPED 	bit(0)
 /*
  * EFF_XY / EFF_OWNER / EFF_GROUP assert that coordinates / owner /
  * group of such a table's entries can be safely obtained by
- * dereferencing entry address cast to struct empobj *.
+ * dereferencing the entry's address cast to struct empobj *.
  */
-#define EFF_XY		bit(0)
-#define EFF_OWNER	bit(1)
-#define EFF_GROUP	bit(2)
+#define EFF_XY		bit(1)
+#define EFF_OWNER	bit(2)
+#define EFF_GROUP	bit(3)
 /* Table is allocated statically */
-#define EFF_STATIC	bit(3)
+#define EFF_STATIC	bit(4)
 /* All the immutable flags */
-#define EFF_IMMUTABLE	(EFF_XY | EFF_OWNER | EFF_GROUP | EFF_STATIC)
+#define EFF_IMMUTABLE \
+    (EFF_TYPED | EFF_XY | EFF_OWNER | EFF_GROUP | EFF_STATIC)
 /* Flags set when table contents is mapped */
 /* Table is entirely in memory */
 #define EFF_MEM		bit(8)
diff --git a/src/lib/global/file.c b/src/lib/global/file.c
index 0a0031a6..5e6ec469 100644
--- a/src/lib/global/file.c
+++ b/src/lib/global/file.c
@@ -117,39 +117,42 @@ struct empfile empfile[] = {
      * Fixed up by empfile_fixup().
      */
     {EF_SECTOR, "sect", "sector", sect_ca,
-     UNMAPPED_CACHE(struct sctstr, EFF_XY | EFF_OWNER)},
+     UNMAPPED_CACHE(struct sctstr, EFF_TYPED | EFF_XY | EFF_OWNER)},
     {EF_SHIP, "ship", "ship", ship_ca,
-     UNMAPPED_CACHE(struct shpstr, EFF_XY | EFF_OWNER | EFF_GROUP)},
+     UNMAPPED_CACHE(struct shpstr,
+		    EFF_TYPED | EFF_XY | EFF_OWNER | EFF_GROUP)},
     {EF_PLANE, "plane", "plane", plane_ca,
-     UNMAPPED_CACHE(struct plnstr, EFF_XY | EFF_OWNER | EFF_GROUP)},
+     UNMAPPED_CACHE(struct plnstr,
+		    EFF_TYPED | EFF_XY | EFF_OWNER | EFF_GROUP)},
     {EF_LAND, "land", "land", land_ca,
-     UNMAPPED_CACHE(struct lndstr, EFF_XY | EFF_OWNER | EFF_GROUP)},
+     UNMAPPED_CACHE(struct lndstr,
+		    EFF_TYPED | EFF_XY | EFF_OWNER | EFF_GROUP)},
     {EF_NUKE, "nuke", "nuke", nuke_ca,
-     UNMAPPED_CACHE(struct nukstr, EFF_XY | EFF_OWNER)},
+     UNMAPPED_CACHE(struct nukstr, EFF_TYPED | EFF_XY | EFF_OWNER)},
     {EF_NEWS, "news", "news", news_ca,
-     UNMAPPED_CACHE(struct nwsstr, 0)},
+     UNMAPPED_CACHE(struct nwsstr, EFF_TYPED)},
     {EF_TREATY, "treaty", "treaty", treaty_ca,
-     UNMAPPED_CACHE(struct trtstr, 0)},
+     UNMAPPED_CACHE(struct trtstr, EFF_TYPED)},
     {EF_TRADE, "trade", "trade", trade_ca,
-     UNMAPPED_CACHE(struct trdstr, EFF_OWNER)},
+     UNMAPPED_CACHE(struct trdstr, EFF_TYPED | EFF_OWNER)},
     {EF_POWER, "pow", "power", NULL,
      UNMAPPED_CACHE(struct powstr, 0)},
     {EF_NATION, "nat", "nation", nat_ca,
-     UNMAPPED_CACHE(struct natstr, EFF_OWNER)},
+     UNMAPPED_CACHE(struct natstr, EFF_TYPED | EFF_OWNER)},
     {EF_LOAN, "loan", "loan", loan_ca,
-     UNMAPPED_CACHE(struct lonstr, 0)},
+     UNMAPPED_CACHE(struct lonstr, EFF_TYPED)},
     {EF_MAP, "map", "map", NULL,
      0, 0, NULL, 0, 0, 0, 0, -1, NULL, NULL, NULL},
     {EF_BMAP, "bmap", "bmap", NULL,
      0, 0, NULL, 0, 0, 0, 0, -1, NULL, NULL, NULL},
     {EF_COMM, "commodity", "commodity", commodity_ca,
-     UNMAPPED_CACHE(struct comstr, EFF_OWNER)},
+     UNMAPPED_CACHE(struct comstr, EFF_TYPED | EFF_OWNER)},
     {EF_LOST, "lost", "lostitems", lost_ca,
-     UNMAPPED_CACHE(struct loststr, EFF_OWNER)},
+     UNMAPPED_CACHE(struct loststr, EFF_TYPED | EFF_OWNER)},
     {EF_REALM, "realm", "realms", realm_ca,
-     UNMAPPED_CACHE(struct realmstr, EFF_OWNER)},
+     UNMAPPED_CACHE(struct realmstr, EFF_TYPED | EFF_OWNER)},
     {EF_GAME, "game", "game", game_ca,
-     UNMAPPED_CACHE(struct gamestr, 0)},
+     UNMAPPED_CACHE(struct gamestr, EFF_TYPED)},
 
     /*
      * Static game data (configuration)
@@ -215,7 +218,7 @@ struct empfile empfile[] = {
 
     /* Views */
     {EF_COUNTRY, "country", NULL, cou_ca,
-     UNMAPPED_CACHE(struct natstr, EFF_OWNER)},
+     UNMAPPED_CACHE(struct natstr, EFF_TYPED | EFF_OWNER)},
 
     /* Sentinel */
     {EF_BAD, NULL, NULL, NULL, 0, 0, NULL, 0, 0, 0, 0, -1, NULL, NULL, NULL},