diff --git a/web/database/worker/db-worker.js b/web/database/worker/db-worker.js
index 98c6776e4..f8c8427e7 100644
--- a/web/database/worker/db-worker.js
+++ b/web/database/worker/db-worker.js
@@ -1,102 +1,106 @@
 // @flow
 
 import localforage from 'localforage';
-import initSqlJs from 'sql.js';
+import initSqlJs, { type SqliteDatabase } from 'sql.js';
 
 import {
   type SharedWorkerMessageEvent,
   type WorkerRequestMessage,
   type WorkerResponseMessage,
   workerRequestMessageTypes,
   workerResponseMessageTypes,
   type WorkerRequestProxyMessage,
 } from '../../types/worker-types.js';
 import { SQLITE_CONTENT } from '../utils/constants.js';
 
 const localforageConfig: PartialConfig = {
   driver: localforage.INDEXEDDB,
   name: 'comm',
   storeName: 'commStorage',
   description: 'Comm encrypted database storage',
   version: '1.0',
 };
 localforage.config(localforageConfig);
 
-let sqliteDb = null;
+let sqliteDb: ?SqliteDatabase = null;
 
 async function initDatabase(sqljsFilePath: string, sqljsFilename: ?string) {
   const content = await localforage.getItem(SQLITE_CONTENT);
 
   const locateFile = defaultFilename => {
     if (sqljsFilename) {
       return `${sqljsFilePath}/${sqljsFilename}`;
     }
     return `${sqljsFilePath}/${defaultFilename}`;
   };
   const SQL = await initSqlJs({
     locateFile,
   });
 
   if (content) {
     sqliteDb = new SQL.Database(new Uint8Array(content));
   } else {
     sqliteDb = new SQL.Database();
   }
 
   const versionData = sqliteDb.exec('PRAGMA user_version;');
-  if (versionData.length && versionData[0].values.length) {
-    console.info(`Db version: ${versionData[0].values[0]}`);
+  if (!versionData.length || !versionData[0].values.length) {
+    throw new Error('Error while retrieving database version');
+  }
+  const [dbVersion] = versionData[0].values[0];
+  if (typeof dbVersion === 'number') {
+    console.info(`Db version: ${dbVersion}`);
   } else {
     throw new Error('Error while retrieving database version');
   }
 }
 
 async function processAppRequest(
   message: WorkerRequestMessage,
 ): Promise<?WorkerResponseMessage> {
   if (message.type === workerRequestMessageTypes.PING) {
     return {
       type: workerResponseMessageTypes.PONG,
       text: 'PONG',
     };
   } else if (message.type === workerRequestMessageTypes.INIT) {
     await initDatabase(message.sqljsFilePath, message.sqljsFilename);
     return;
   }
 
   throw new Error('Request type not supported');
 }
 
 function connectHandler(event: SharedWorkerMessageEvent) {
   if (!event.ports.length) {
     return;
   }
   const port: MessagePort = event.ports[0];
   console.log('Web database worker alive!');
 
   port.onmessage = async function (messageEvent: MessageEvent) {
     const data: WorkerRequestProxyMessage = (messageEvent.data: any);
     const { id, message } = data;
 
     if (!id) {
       port.postMessage({
         error: new Error('Request without identifier'),
       });
     }
 
     try {
       const result = await processAppRequest(message);
       port.postMessage({
         id,
         message: result,
       });
     } catch (e) {
       port.postMessage({
         id,
         error: e,
       });
     }
   };
 }
 
 self.addEventListener('connect', connectHandler);
diff --git a/web/flow-typed/npm/sql.js_vx.x.x.js b/web/flow-typed/npm/sql.js_vx.x.x.js
new file mode 100644
index 000000000..a8b06bf4a
--- /dev/null
+++ b/web/flow-typed/npm/sql.js_vx.x.x.js
@@ -0,0 +1,89 @@
+// @flow
+
+// flow-typed signature: f355493becad56880bf30832260c5460
+// flow-typed version: <<STUB>>/sql.js_v1.8.0/flow_v0.182.0
+
+declare module 'sql.js' {
+  declare export type SqlValue = number | string | Uint8Array | null;
+  declare export type ParamsObject = { +[key: string]: SqlValue };
+  declare export type ParamsCallback = (obj: ParamsObject) => void;
+
+  declare export type BindParams =
+    | $ReadOnlyArray<SqlValue>
+    | ParamsObject
+    | null;
+
+  declare export type QueryExecResult = {
+    columns: string[],
+    values: SqlValue[][],
+  };
+
+  declare export type StatementIteratorResult = {
+    +done: boolean,
+    +value: SqliteStatement,
+  };
+
+  declare export type SqlJsStatic = {
+    +Database: Class<SqliteDatabase>,
+    +Statement: Class<SqliteStatement>,
+  };
+
+  declare type EmscriptenModule = {
+    +locateFile: (path: string, prefix?: string) => string,
+    ...
+  };
+
+  declare type InitSqlJsStatic = {
+    (config?: EmscriptenModule): Promise<SqlJsStatic>,
+  };
+
+  declare export class SqliteDatabase {
+    constructor(data?: Array<number> | Uint8Array | Buffer | null): this;
+    close(): void;
+
+    create_function<T, R>(
+      name: string,
+      func: (...args: $ReadOnlyArray<T>) => R,
+    ): SqliteDatabase;
+    each(
+      sql: string,
+      params: BindParams,
+      callback: ParamsCallback,
+      done: () => void,
+    ): SqliteDatabase;
+    each(
+      sql: string,
+      callback: ParamsCallback,
+      done: () => void,
+    ): SqliteDatabase;
+    exec(sql: string, params?: BindParams): QueryExecResult[];
+    export(): Uint8Array;
+    getRowsModified(): number;
+    handleError(): null | empty;
+    iterateStatements(sql: string): StatementIterator;
+    prepare(sql: string, params?: BindParams): SqliteStatement;
+    run(sql: string, params?: BindParams): SqliteDatabase;
+  }
+
+  declare export class SqliteStatement {
+    bind(values?: BindParams): boolean;
+    free(): boolean;
+    freemem(): void;
+    get(params?: BindParams): $ReadOnlyArray<SqlValue>;
+    getAsObject(params?: BindParams): ParamsObject;
+    getColumnNames(): $ReadOnlyArray<string>;
+    getNormalizedSQL(): string;
+    getSQL(): string;
+    reset(): void;
+    run(values?: BindParams): void;
+    step(): boolean;
+  }
+
+  declare export class StatementIterator implements Iterable<SqliteStatement> {
+    @@iterator: () => Iterator<SqliteStatement>;
+    getRemainingSql(): string;
+    next(): StatementIteratorResult;
+  }
+
+  declare export default InitSqlJsStatic;
+}