diff --git a/src/nhlua.c b/src/nhlua.c
index ab5ccc694..dafee5753 100644
--- a/src/nhlua.c
+++ b/src/nhlua.c
@@ -487,6 +487,20 @@ nhl_getmap(lua_State *L)
         nhl_error(L, "Incorrect arguments");
         return 0;
     }
+    if (g.in_mklev) {
+        /* xstart and ystart are set by the des.map() command to give
+         * coordinates relative to the 0,0 of that map. It can be quite useful
+         * to check what terrain is on a given space. But without compensating
+         * for the change in xstart and ystart here, this will lead to results
+         * like des.terrain(4,6,'L') and then nh.getmap(4,6) not being lava.
+         *
+         * Only valid during mklev, because xstart and ystart are not saved
+         * with the level and can change during the level creating process when
+         * additional des.map() are executed. They will not necessarily be the
+         * same later. */
+        x += g.xstart;
+        y += g.ystart;
+    }
 
     x = (coordxy) lx;
     y = (coordxy) ly;