diff --git a/src/objnam.c b/src/objnam.c
index a3688b7a5..a232d7860 100644
--- a/src/objnam.c
+++ b/src/objnam.c
@@ -12,7 +12,7 @@
 
 STATIC_DCL char *FDECL(strprepend, (char *, const char *));
 STATIC_DCL short FDECL(rnd_otyp_by_wpnskill, (SCHAR_P));
-STATIC_DCL short FDECL(rnd_otyp_by_namedesc, (char *, CHAR_P));
+STATIC_DCL short FDECL(rnd_otyp_by_namedesc, (const char *, CHAR_P));
 STATIC_DCL boolean FDECL(wishymatch, (const char *, const char *, BOOLEAN_P));
 STATIC_DCL char *NDECL(nextobuf);
 STATIC_DCL void FDECL(releaseobuf, (char *));
@@ -2693,6 +2693,7 @@ schar skill;
 {
     int i, n = 0;
     short otyp = STRANGE_OBJECT;
+
     for (i = bases[WEAPON_CLASS];
          i < NUM_OBJECTS && objects[i].oc_class == WEAPON_CLASS; i++)
         if (objects[i].oc_skill == skill) {
@@ -2712,15 +2713,15 @@ schar skill;
 
 STATIC_OVL short
 rnd_otyp_by_namedesc(name, oclass)
-char *name;
+const char *name;
 char oclass;
 {
     int i, n = 0;
     short validobjs[NUM_OBJECTS];
     register const char *zn;
-    long maxprob = 0;
+    int prob, maxprob = 0;
 
-    if (!name)
+    if (!name || !*name)
         return STRANGE_OBJECT;
 
     memset((genericptr_t) validobjs, 0, sizeof validobjs);
@@ -2737,17 +2738,15 @@ char oclass;
             || ((zn = objects[i].oc_uname) != 0
                 && wishymatch(name, zn, FALSE))) {
             validobjs[n++] = (short) i;
-            maxprob += (objects[i].oc_prob + 1);
+            maxprob += objects[i].oc_prob;
         }
     }
 
     if (n > 0 && maxprob) {
-        long prob = rn2(maxprob);
-
-        i = 0;
-        while (i < n - 1
-               && (prob -= (objects[validobjs[i]].oc_prob + 1)) >= 0)
-            i++;
+        prob = rn2(maxprob);
+        for (i = 0; i < n - 1; i++)
+            if ((prob -= objects[validobjs[i]].oc_prob) < 0)
+                break;
         return validobjs[i];
     }
     return STRANGE_OBJECT;