diff --git a/doc/fixes3-7-0.txt b/doc/fixes3-7-0.txt
index c98cd28e5..d2b0a4964 100644
--- a/doc/fixes3-7-0.txt
+++ b/doc/fixes3-7-0.txt
@@ -1506,6 +1506,7 @@ since introduction in 3.1.0, the definition for Mitre of Holiness has specified
 	no 'defends' capability for it since carrying should encompass that
 if a tree and a boulder or statue were at the same location, applying an axe
 	would break the boulder or statue rather than chop the tree
+avoid premapping outside Sokoban map to prevent showing stone glyphs
 
 
 Fixes to 3.7.0-x General Problems Exposed Via git Repository
diff --git a/src/detect.c b/src/detect.c
index cb6dc2458..0d1de0c83 100644
--- a/src/detect.c
+++ b/src/detect.c
@@ -38,6 +38,7 @@ staticfn void foundone(coordxy, coordxy, int);
 staticfn void findone(coordxy, coordxy, genericptr_t);
 staticfn void openone(coordxy, coordxy, genericptr_t);
 staticfn int mfind0(struct monst *, boolean);
+staticfn boolean skip_premap_detect(coordxy, coordxy);
 staticfn int reveal_terrain_getglyph(coordxy, coordxy, unsigned, int,
                                      unsigned);
 
@@ -2117,6 +2118,16 @@ warnreveal(void)
         }
 }
 
+/* skip premap detection of areas outside Sokoban map */
+staticfn boolean
+skip_premap_detect(coordxy x, coordxy y)
+{
+    if ((levl[x][y].typ == STONE)
+        && (levl[x][y].wall_info & (W_NONDIGGABLE | W_NONPASSWALL)) != 0)
+        return TRUE;
+    return FALSE;
+}
+
 /* Pre-map (the sokoban) levels */
 void
 premap_detect(void)
@@ -2128,6 +2139,8 @@ premap_detect(void)
     /* Map the background and boulders */
     for (x = 1; x < COLNO; x++)
         for (y = 0; y < ROWNO; y++) {
+            if (skip_premap_detect(x, y))
+                continue;
             levl[x][y].seenv = SVALL;
             levl[x][y].waslit = TRUE;
             if (levl[x][y].typ == SDOOR)