diff --git a/advent.h b/advent.h
index 6d83807..17ae719 100644
--- a/advent.h
+++ b/advent.h
@@ -165,7 +165,7 @@ struct game_t {
     loc_t dloc[NDWARVES + 1];    // location of dwarves, initially hard-wired in
     loc_t odloc[NDWARVES + 1];   // prior loc of each dwarf, initially garbage
     loc_t fixed[NOBJECTS + 1];   // fixed location of object (if  not IS_FREE)
-    long link[NOBJECTS * 2 + 1]; // object-list links
+    obj_t link[NOBJECTS * 2 + 1]; // object-list links
     loc_t place[NOBJECTS + 1];   // location of object
     long hinted[NHINTS];         // hinted[i] = true iff hint i has been used.
     long hintlc[NHINTS];         // hintlc[i] = how long at LOC with cond bit i
diff --git a/saveresume.c b/saveresume.c
index 6027096..4378324 100644
--- a/saveresume.c
+++ b/saveresume.c
@@ -185,7 +185,7 @@ bool is_valid(struct game_t valgame)
     }
 
     /* Check that properties of objects aren't beyond expected */
-    for (int obj = 0; obj <= NOBJECTS; obj++) {
+    for (obj_t obj = 0; obj <= NOBJECTS; obj++) {
         if (valgame.prop[obj] < STATE_NOTFOUND || valgame.prop[obj] > 1) {
             switch (obj) {
             case RUG:
@@ -210,9 +210,14 @@ bool is_valid(struct game_t valgame)
         }
     }
 
-    /* Check that we have objects at locations */
+    /* Check that values in linked lists for objects in locations are inside bounds */
     for (loc_t loc = LOC_NOWHERE; loc <= NLOCATIONS; loc++) {
-        if (valgame.atloc[loc] < NO_OBJECT || valgame.atloc[loc] > NOBJECTS * 2 + 1) {
+        if (valgame.atloc[loc] < NO_OBJECT || valgame.atloc[loc] > NOBJECTS * 2) {
+            return false;
+        }
+    }
+    for (obj_t obj = 0; obj <= NOBJECTS * 2; obj++ ) {
+        if (valgame.link[obj] < NO_OBJECT || valgame.link[obj] > NOBJECTS * 2) {
             return false;
         }
     }