diff --git a/fixup.sh b/fixup.sh
index 67e09214..bd912764 100755
--- a/fixup.sh
+++ b/fixup.sh
@@ -1,13 +1,14 @@
 #!/bin/sh
 
-cat >build/cjs/package.json <<!EOF
-{
-    "type": "commonjs"
-}
-!EOF
+package_version=`npm show . version`
 
-cat >build/esm/package.json <<!EOF
+for target in esm cjs; do
+    cp -R certs build/$target/src/
+    [[ $target == "esm" ]] && type="module" || type="commonjs"
+    cat >build/$target/package.json <<!EOF
 {
-    "type": "module"
+    "version": "$package_version",
+    "type": "$type"
 }
 !EOF
+done
diff --git a/package.json b/package.json
index 4da188a3..e6a81863 100644
--- a/package.json
+++ b/package.json
@@ -2,17 +2,16 @@
   "name": "ydb-sdk",
   "version": "3.4.0",
   "description": "Node.js bindings for working with YDB API over gRPC",
-  "main": "build/cjs/index.js",
-  "module": "build/esm/index.js",
+  "main": "build/cjs/src/index.js",
+  "module": "build/esm/src/index.js",
   "exports": {
     ".": {
-      "import": "./build/esm/index.js",
-      "require": "./build/cjs/index.js"
+      "import": "./build/esm/src/index.js",
+      "require": "./build/cjs/src/index.js"
     }
   },
   "files": [
-    "build/**",
-    "certs/"
+    "build/**"
   ],
   "scripts": {
     "test:unit": "exit 0",
diff --git a/src/ssl-credentials.ts b/src/ssl-credentials.ts
index 549e4483..c6812c6a 100644
--- a/src/ssl-credentials.ts
+++ b/src/ssl-credentials.ts
@@ -1,22 +1,30 @@
 // noinspection ES6PreferShortImport
-import {Logger} from './logging';
+import { Logger } from './logging';
 import fs from 'fs';
 import path from 'path';
-import {getRelTopLevelPath} from "./version";
 
-const FALLBACK_INTERNAL_ROOT_CERTS = path.join(__dirname, getRelTopLevelPath(), 'certs/internal.pem');
-const FALLBACK_SYSTEM_ROOT_CERTS = path.join(__dirname, getRelTopLevelPath(), 'certs/system.pem');
+const CERTIFICATES_FOLDER = 'certs'
+const RELATIVE_PATH = process.env.TEST_ENVIRONMENT ? '../' : './'
+const RESOLVED_PATH = path.join(__dirname, RELATIVE_PATH, CERTIFICATES_FOLDER)
+const FALLBACK_INTERNAL_ROOT_CERTS = path.join(RESOLVED_PATH, 'internal.pem');
+const FALLBACK_SYSTEM_ROOT_CERTS = path.join(RESOLVED_PATH, 'system.pem');
 
 function makeInternalRootCertificates() {
-    const internalRootCertificates = fs.readFileSync(FALLBACK_INTERNAL_ROOT_CERTS);
+    if (!fs.existsSync(FALLBACK_INTERNAL_ROOT_CERTS)
+     || !fs.existsSync(FALLBACK_SYSTEM_ROOT_CERTS)) {
+        throw new Error(certificateNotFoundMessage)
+    }
+
+    const internalRootCertificates = fs.readFileSync(FALLBACK_INTERNAL_ROOT_CERTS)
+    const fallbackSystemRootCertificates = fs.readFileSync(FALLBACK_SYSTEM_ROOT_CERTS)
 
-    let systemRootCertificates;
+    let systemRootCertificates: Buffer;
     const tls = require('tls');
     const nodeRootCertificates = tls.rootCertificates as string[] | undefined;
     if (nodeRootCertificates && nodeRootCertificates.length > 0) {
         systemRootCertificates = Buffer.from(nodeRootCertificates.join('\n'));
     } else {
-        systemRootCertificates = fs.readFileSync(FALLBACK_SYSTEM_ROOT_CERTS);
+        systemRootCertificates = fallbackSystemRootCertificates;
     }
 
     return Buffer.concat([internalRootCertificates, systemRootCertificates]);
@@ -47,6 +55,12 @@ export function makeSslCredentials(endpoint: string, logger: Logger, sslCredenti
     return makeDefaultSslCredentials();
 }
 
+const certificateNotFoundMessage = `No certificate found
+It seems that you are using grpcs (secure) endpoint in a bundled environment.
+Either provide YDB_SSL_ROOT_CERTIFICATES_FILE environment variable
+or copy contents of ydb-nodejs-sdk/certs to ./certs path relative to the bundled file
+`
+
 export interface ISslCredentials {
     rootCertificates?: Buffer,
     clientPrivateKey?: Buffer,
diff --git a/src/version.ts b/src/version.ts
index de97a84c..104f1423 100644
--- a/src/version.ts
+++ b/src/version.ts
@@ -1,10 +1,4 @@
-import path from 'path';
-
-export function getRelTopLevelPath() {
-    return process.env.TEST_ENVIRONMENT === 'dev' ? '..' : '../..';
-}
-
-const pkgInfo = require(path.join(getRelTopLevelPath(), 'package.json'));
+import pkgInfo from "./../package.json";
 
 function getVersion() {
     return pkgInfo.version;
diff --git a/tsconfig-base.json b/tsconfig-base.json
index dbd3881f..0eb9dbd3 100644
--- a/tsconfig-base.json
+++ b/tsconfig-base.json
@@ -15,7 +15,8 @@
     "skipLibCheck": true,
     "experimentalDecorators": true,
     "allowJs": true,
-    "declaration": true
+    "declaration": true,
+    "resolveJsonModule": true
   },
   "include": [
     "src/**/*.ts"