diff --git a/js/main-editor.js b/js/main-editor.js
index 48aa342..f530883 100644
--- a/js/main-editor.js
+++ b/js/main-editor.js
@@ -1906,6 +1906,7 @@ const EDITOR_PALETTE = [{
         'sokoban_block/yellow',
         'sokoban_button/yellow',
         'sokoban_wall/yellow',
+        'one_way_walls/south',
     ],
 }];
 
@@ -2584,6 +2585,7 @@ const SPECIAL_PALETTE_ENTRIES = {
     'sokoban_block/green':  { name: 'sokoban_block', color: 'green' },
     'sokoban_button/green': { name: 'sokoban_button', color: 'green' },
     'sokoban_wall/green':   { name: 'sokoban_wall', color: 'green' },
+    'one_way_walls/south':  { name: 'one_way_walls', edges: DIRECTIONS['south'].bit },
 };
 const _RAILROAD_ROTATED_LEFT = [3, 0, 1, 2, 5, 4];
 const _RAILROAD_ROTATED_RIGHT = [1, 2, 3, 0, 5, 4];
@@ -2815,6 +2817,15 @@ const SPECIAL_PALETTE_BEHAVIOR = {
             return 'sokoban_wall/' + (tile.color ?? 'red');
         },
     },
+    one_way_walls: {
+        pick_palette_entry(tile) {
+            return 'one_way_walls/south';
+        },
+    },
+};
+SPECIAL_PALETTE_BEHAVIOR['one_way_walls'] = {
+    ...SPECIAL_PALETTE_BEHAVIOR['thin_walls'],
+    ...SPECIAL_PALETTE_BEHAVIOR['one_way_walls'],
 };
 // Fill in some special behavior that boils down to rotating tiles which happen to be encoded as
 // different tile types
diff --git a/js/tileset.js b/js/tileset.js
index 113b3c0..0c7bf0f 100644
--- a/js/tileset.js
+++ b/js/tileset.js
@@ -1154,6 +1154,11 @@ export const LL_TILESET_LAYOUT = {
         thin_walls_ns: [8, 4],
         thin_walls_ew: [8, 5],
     },
+    one_way_walls: {
+        __special__: 'thin_walls',
+        thin_walls_ns: [9, 4],
+        thin_walls_ew: [9, 5],
+    },
 
     force_floor_n: {
         __special__: 'scroll',
diff --git a/js/tiletypes.js b/js/tiletypes.js
index 1dd0f6f..24540f4 100644
--- a/js/tiletypes.js
+++ b/js/tiletypes.js
@@ -376,10 +376,27 @@ const TILE_TYPES = {
     thin_walls: {
         layer: LAYERS.thin_wall,
         blocks(me, level, actor, direction) {
-            return ((me.edges & DIRECTIONS[direction].opposite_bit) !== 0) && actor.type.name !== 'ghost';
+            if (actor.type.name === 'ghost')
+                return false;
+            return (me.edges & DIRECTIONS[direction].opposite_bit) !== 0;
         },
         blocks_leaving(me, actor, direction) {
-            return ((me.edges & DIRECTIONS[direction].bit) !== 0) && actor.type.name !== 'ghost';
+            if (actor.type.name === 'ghost')
+                return false;
+            return (me.edges & DIRECTIONS[direction].bit) !== 0;
+        },
+        populate_defaults(me) {
+            me.edges = 0;  // bitmask of directions
+        },
+    },
+    // These only support one-way into the tile, so they're pretty much thin walls that can only
+    // stop something from leaving
+    one_way_walls: {
+        layer: LAYERS.thin_wall,
+        blocks_leaving(me, actor, direction) {
+            if (actor.type.name === 'ghost')
+                return false;
+            return (me.edges & DIRECTIONS[direction].bit) !== 0;
         },
         populate_defaults(me) {
             me.edges = 0;  // bitmask of directions