diff --git a/limmutable.c b/limmutable.c
index 19d4e80..5208f48 100644
--- a/limmutable.c
+++ b/limmutable.c
@@ -185,27 +185,27 @@ static int Lindex(lua_State *L)
 {
     lua_getmetatable(L, 1);
     // Stack: [mt]
-    lua_getfield(L, -1, "__field_positions");
-    // Stack: [mt, field_positions]
+    lua_getfield(L, -1, "__indices");
+    // Stack: [mt, indices]
     lua_pushvalue(L, 2);
-    // Stack: [mt, field_positions, k]
+    // Stack: [mt, indices, k]
     lua_rawget(L, -2);
-    // Stack: [mt, field_positions, i]
+    // Stack: [mt, indices, i]
     if (! lua_isnil(L, -1)) {
-        // Stack: [mt, field_positions, i]
+        // Stack: [mt, indices, i]
         lua_getfield(L, -3, "__instances");
-        // Stack: [mt, field_positions, i, buckets]
+        // Stack: [mt, indices, i, buckets]
         lua_rawgeti(L, -1, *((lua_Integer*)lua_touserdata(L, 1)));
-        // Stack: [mt, field_positions, i, buckets, bucket]
+        // Stack: [mt, indices, i, buckets, bucket]
         lua_pushvalue(L, 1);
-        // Stack: [mt, field_positions, i, buckets, bucket, inst_udata]
+        // Stack: [mt, indices, i, buckets, bucket, inst_udata]
         lua_rawget(L, -2);
-        // Stack: [mt, field_positions, i, buckets, bucket, inst_table]
+        // Stack: [mt, indices, i, buckets, bucket, inst_table]
         lua_rawgeti(L, -1, lua_tointeger(L, -4));
         return 1;
     }
     // Fall back to class:
-    // Stack: [mt, field_positions, i]
+    // Stack: [mt, indices, i]
     lua_pop(L, 2);
     // Stack: [mt]
     lua_pushvalue(L, 2);
@@ -321,7 +321,7 @@ static int Lnext(lua_State *L)
     // Stack: [mt, buckets, bucket, inst_udata]
     lua_rawget(L, -2);
     // Stack: [mt, buckets, bucket, inst_table]
-    lua_getfield(L, -4, "__field_positions");
+    lua_getfield(L, -4, "__indices");
     // Stack: [mt, buckets, bucket, inst_table, fields]
     lua_pushvalue(L, 2);
     // Stack: [mt, buckets, bucket, inst_table, fields, k]
@@ -395,16 +395,16 @@ static int Lmake_class(lua_State *L)
     
     size_t n = lua_objlen(L, 1);
     lua_createtable(L, 0, n);
-    // Stack: [CLS, __field_positions]
+    // Stack: [CLS, __indices]
     lua_pushnil(L);
     while (lua_next(L, 1) != 0) {
-        // Stack: [CLS, __field_positions, i, fieldname]
+        // Stack: [CLS, __indices, i, fieldname]
         lua_pushvalue(L, -2);
-        // Stack: [CLS, __field_positions, i, fieldname, i]
+        // Stack: [CLS, __indices, i, fieldname, i]
         lua_settable(L, -4);
-        // Stack: [CLS, __field_positions, i]
+        // Stack: [CLS, __indices, i]
     }
-    lua_setfield(L, -2, "__field_positions");
+    lua_setfield(L, -2, "__indices");
     // Stack: [CLS]
 
     // If methods were passed in, copy them over