diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5f2fbdb..6342aad 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -102,3 +102,8 @@ Format: [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 
 ### Fixed
 - Labels stored as label.text (e.g. from MCP updates) now survive page refresh — expandLabelsToNative pre-converts them to bound text before Excalidraw renders
+
+## [1.0.4] - 2026-03-31
+
+### Fixed
+- `npm install -g excalidraw-mcp-sentinel` crashed on Windows — `postinstall` script used Unix-only `2>/dev/null || true` syntax which cmd.exe does not support; replaced with a cross-platform `node -e` inline script
diff --git a/package-lock.json b/package-lock.json
index ecea6cb..65f8e7c 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "excalidraw-mcp-sentinel",
-  "version": "1.0.1",
+  "version": "1.0.3",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "excalidraw-mcp-sentinel",
-      "version": "1.0.1",
+      "version": "1.0.3",
       "hasInstallScript": true,
       "license": "MIT",
       "dependencies": {
@@ -25,7 +25,7 @@
         "react-dom": "^18.3.1",
         "winston": "^3.11.0",
         "ws": "8.20.0",
-        "zod": "3.25.5",
+        "zod": "^4.3.6",
         "zod-to-json-schema": "^3.22.3"
       },
       "bin": {
@@ -1572,15 +1572,6 @@
         "node": ">= 0.6"
       }
     },
-    "node_modules/@modelcontextprotocol/sdk/node_modules/zod": {
-      "version": "4.3.6",
-      "resolved": "https://registry.npmjs.org/zod/-/zod-4.3.6.tgz",
-      "integrity": "sha512-rftlrkhHZOcjDwkGlnUtZZkvaPHCsDATp4pGpuOOMDaTdDDXF91wuVDJoWoPsKX/3YPQ5fHuF3STjcYyKr+Qhg==",
-      "license": "MIT",
-      "funding": {
-        "url": "https://github.com/sponsors/colinhacks"
-      }
-    },
     "node_modules/@noble/hashes": {
       "version": "1.8.0",
       "resolved": "https://registry.npmjs.org/@noble/hashes/-/hashes-1.8.0.tgz",
@@ -9138,9 +9129,9 @@
       }
     },
     "node_modules/zod": {
-      "version": "3.25.5",
-      "resolved": "https://registry.npmjs.org/zod/-/zod-3.25.5.tgz",
-      "integrity": "sha512-ualArhgJydGAKkSdtxQyu6RXFW8nHFKWaw20jey8UFXU9uzkHYqWXJ93Iz+hUVVJb37VpF4LCCsOOfj6xaCVRQ==",
+      "version": "4.3.6",
+      "resolved": "https://registry.npmjs.org/zod/-/zod-4.3.6.tgz",
+      "integrity": "sha512-rftlrkhHZOcjDwkGlnUtZZkvaPHCsDATp4pGpuOOMDaTdDDXF91wuVDJoWoPsKX/3YPQ5fHuF3STjcYyKr+Qhg==",
       "license": "MIT",
       "peer": true,
       "funding": {
diff --git a/package.json b/package.json
index 140d7fc..abd77a8 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "excalidraw-mcp-sentinel",
-  "version": "1.0.3",
+  "version": "1.0.4",
   "description": "Hardened, self-hosted Excalidraw MCP server with SQLite persistence, multi-tenancy, auto-sync, security middleware, and 369 tests",
   "main": "dist/index.js",
   "type": "module",