diff --git a/package.json b/package.json
index e087c07..3cabfe7 100644
--- a/package.json
+++ b/package.json
@@ -37,7 +37,7 @@
     "prettier": "1.19.1",
     "reflect-metadata": "0.1.13",
     "rimraf": "3.0.1",
-    "rxjs": "7.1.0",
+    "rxjs": "^6.0.0",
     "standard-version": "8.0.2",
     "ts-jest": "24.3.0",
     "ts-node": "10.0.0",
@@ -48,7 +48,7 @@
     "@nestjs/common": "7.6.15",
     "@nestjs/core": "7.6.15",
     "reflect-metadata": "^0.1.12",
-    "rxjs": "^6.2.2 || ^7.0.0"
+    "rxjs": "^6.0.0"
   },
   "repository": {
     "type": "git",
diff --git a/src/services/authz-management.service.ts b/src/services/authz-management.service.ts
index 574dceb..222c627 100644
--- a/src/services/authz-management.service.ts
+++ b/src/services/authz-management.service.ts
@@ -527,7 +527,6 @@ export class AuthZManagementService {
     return this.enforcer.addFunction(name, func);
   }
 
-
   /**
    * loadPolicy reloads the policy from file/database.
    */
diff --git a/tsconfig.json b/tsconfig.json
index fe6792e..58c08da 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -10,7 +10,7 @@
     "noImplicitReturns": true,
     "strictNullChecks": true,
     "stripInternal": true,
-    "target": "es5",
+    "target": "es6",
     "outDir": "./dist",
     "baseUrl": "./"
   },
diff --git a/yarn.lock b/yarn.lock
index b7bce6c..b842bf4 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -4479,12 +4479,12 @@ run-async@^2.2.0:
   resolved "https://registry.yarnpkg.com/run-async/-/run-async-2.4.1.tgz#8440eccf99ea3e70bd409d49aab88e10c189a455"
   integrity sha512-tvVnVv01b8c1RrA6Ep7JkStj85Guv/YrMcwqYQnwjsAS2cTmmPGBBjAjpCW7RrSodNSoE2/qg9O4bceNvUuDgQ==
 
-rxjs@7.1.0:
-  version "7.1.0"
-  resolved "https://registry.yarnpkg.com/rxjs/-/rxjs-7.1.0.tgz#94202d27b19305ef7b1a4f330277b2065df7039e"
-  integrity sha512-gCFO5iHIbRPwznl6hAYuwNFld8W4S2shtSJIqG27ReWXo9IWrCyEICxUA+6vJHwSR/OakoenC4QsDxq50tzYmw==
+rxjs@^6.0.0:
+  version "6.6.7"
+  resolved "https://registry.npmjs.org/rxjs/-/rxjs-6.6.7.tgz#90ac018acabf491bf65044235d5863c4dab804c9"
+  integrity sha512-hTdwr+7yYNIT5n4AMYp85KA6yw2Va0FLa3Rguvbpa4W3I5xynaBZo41cM3XM+4Q6fRMj3sBYIR1VAmZMXYJvRQ==
   dependencies:
-    tslib "~2.1.0"
+    tslib "^1.9.0"
 
 rxjs@^6.4.0:
   version "6.5.5"
@@ -5141,7 +5141,7 @@ ts-node@10.0.0:
     source-map-support "^0.5.17"
     yn "3.1.1"
 
-tslib@2.1.0, tslib@~2.1.0:
+tslib@2.1.0:
   version "2.1.0"
   resolved "https://registry.yarnpkg.com/tslib/-/tslib-2.1.0.tgz#da60860f1c2ecaa5703ab7d39bc05b6bf988b97a"
   integrity sha512-hcVC3wYEziELGGmEEXue7D75zbwIIVUMWAVbHItGPx0ziyXxrOMQx4rQEVEV45Ut/1IotuEvwqPopzIOkDMf0A==