diff --git a/CHANGELOG.md b/CHANGELOG.md
index b58d719..5f2fbdb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,12 @@ Format: [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 
 ## [Unreleased]
 
+## [1.0.3] - 2026-03-30
+
+### Fixed
+- Global install crash (`Schema method literal must be a string`) — upgraded `zod` from `3.25.5` to `^4.3.6` so the package uses real zod v4 rather than falling back to zod 3.x's v4 compatibility shim, which lacks the `.value` getter required by `@modelcontextprotocol/sdk@1.26.0`
+- `z.record(z.any())` call updated to `z.record(z.string(), z.any())` to satisfy zod v4's stricter record key-type requirement
+
 ## [1.0.2] - 2026-03-30
 
 ### Added
diff --git a/package.json b/package.json
index 2e86d1d..03dbe03 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "excalidraw-mcp-sentinel",
-  "version": "1.0.2",
+  "version": "1.0.3",
   "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",
@@ -47,7 +47,7 @@
     "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"
   },
   "devDependencies": {
diff --git a/src/index.ts b/src/index.ts
index 33b1022..be3e649 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -378,7 +378,7 @@ const DistributeElementsSchema = z.object({
 
 const QuerySchema = z.object({
   type: z.enum(Object.values(EXCALIDRAW_ELEMENT_TYPES) as [ExcalidrawElementType, ...ExcalidrawElementType[]]).optional(),
-  filter: z.record(z.any()).optional()
+  filter: z.record(z.string(), z.any()).optional()
 });
 
 const ResourceSchema = z.object({