diff --git a/svelte-app/src/lib/serialization.ts b/svelte-app/src/lib/serialization.ts
index c887c08..43e2559 100644
--- a/svelte-app/src/lib/serialization.ts
+++ b/svelte-app/src/lib/serialization.ts
@@ -1,4 +1,14 @@
 import type { PlacedSymbol, EpcWaypoint } from './types.js';
+import { SYMBOLS } from './symbols.js';
+
+/** Map of symbolId → current default {w, h} for migration */
+const DEFAULT_SIZES = new Map(SYMBOLS.map(s => [s.id, { w: s.w, h: s.h }]));
+
+/** Known outdated defaults: symbolId → [{oldW, oldH}] */
+const OUTDATED_SIZES: Record<string, { w: number; h: number }[]> = {
+  photoeye:   [{ w: 56, h: 20 }],
+  photoeye_v: [{ w: 56, h: 20 }],
+};
 
 /** JSON shape stored in localStorage / exported JSON files */
 export interface SerializedSymbol {
@@ -38,6 +48,18 @@ export function serializeSymbol(sym: PlacedSymbol): SerializedSymbol {
 }
 
 export function deserializeSymbol(data: SerializedSymbol, id: number): PlacedSymbol {
+  let { w, h } = data;
+
+  // Migrate outdated default sizes to current defaults
+  const outdated = OUTDATED_SIZES[data.symbolId];
+  if (outdated) {
+    const current = DEFAULT_SIZES.get(data.symbolId);
+    if (current && outdated.some(o => o.w === w && o.h === h)) {
+      w = current.w;
+      h = current.h;
+    }
+  }
+
   return {
     id,
     symbolId: data.symbolId,
@@ -46,8 +68,8 @@ export function deserializeSymbol(data: SerializedSymbol, id: number): PlacedSym
     file: data.file?.replace('_no_comm.svg', '.svg') || data.file,
     x: data.x,
     y: data.y,
-    w: data.w,
-    h: data.h,
+    w,
+    h,
     w2: data.w2,
     rotation: data.rotation || 0,
     mirrored: data.mirrored || false,