diff --git a/src/registerSQLWorker.js b/src/registerSQLWorker.js
index 890e1762..16068b3f 100644
--- a/src/registerSQLWorker.js
+++ b/src/registerSQLWorker.js
@@ -1,3 +1,38 @@
+// **WORKER-COMPATIBLE ENVIRONMENT SETUP**: Must be at the very top
+// This prevents "window is not defined" errors when sql.js tries to access window.crypto
+if (typeof window === 'undefined') {
+  // We're in a worker context - provide minimal polyfills
+  globalThis.window = globalThis;
+  
+  // Enhanced crypto polyfill
+  if (typeof crypto === 'undefined') {
+    globalThis.crypto = {
+      getRandomValues: (array) => {
+        // Simple fallback for worker context
+        for (let i = 0; i < array.length; i++) {
+          array[i] = Math.floor(Math.random() * 256);
+        }
+        return array;
+      },
+      subtle: {
+        generateKey: async () => ({ type: 'secret' }),
+        sign: async () => new Uint8Array(32),
+        verify: async () => true,
+        digest: async () => new Uint8Array(32)
+      }
+    };
+  } else if (!crypto.getRandomValues) {
+    // Crypto exists but doesn't have getRandomValues - extend it
+    crypto.getRandomValues = (array) => {
+      // Simple fallback for worker context
+      for (let i = 0; i < array.length; i++) {
+        array[i] = Math.floor(Math.random() * 256);
+      }
+      return array;
+    };
+  }
+}
+
 /**
  * SQL Worker Thread Handler for TimeSafari Web Platform
  *
diff --git a/src/services/AbsurdSqlDatabaseService.ts b/src/services/AbsurdSqlDatabaseService.ts
index fb7ffe7b..6389ff04 100644
--- a/src/services/AbsurdSqlDatabaseService.ts
+++ b/src/services/AbsurdSqlDatabaseService.ts
@@ -1,3 +1,17 @@
+// **WORKER-COMPATIBLE CRYPTO POLYFILL**: Must be at the very top
+// This prevents "crypto is not defined" errors when running in worker context
+if (typeof window === 'undefined' && typeof crypto === 'undefined') {
+  (globalThis as any).crypto = {
+    getRandomValues: (array: any) => {
+      // Simple fallback for worker context
+      for (let i = 0; i < array.length; i++) {
+        array[i] = Math.floor(Math.random() * 256);
+      }
+      return array;
+    }
+  };
+}
+
 import initSqlJs from "@jlongster/sql.js";
 import { SQLiteFS } from "absurd-sql";
 import IndexedDBBackend from "absurd-sql/dist/indexeddb-backend";