diff --git a/packages/pg/lib/connection-parameters.js b/packages/pg/lib/connection-parameters.js
index a7b941c10..c153932bb 100644
--- a/packages/pg/lib/connection-parameters.js
+++ b/packages/pg/lib/connection-parameters.js
@@ -7,6 +7,10 @@ const defaults = require('./defaults')
 const parse = require('pg-connection-string').parse // parses a connection string
 
 const val = function (key, config, envVar) {
+  if (config[key]) {
+    return config[key]
+  }
+
   if (envVar === undefined) {
     envVar = process.env['PG' + key.toUpperCase()]
   } else if (envVar === false) {
@@ -15,7 +19,7 @@ const val = function (key, config, envVar) {
     envVar = process.env[envVar]
   }
 
-  return config[key] || envVar || defaults[key]
+  return envVar || defaults[key]
 }
 
 const readSSLConfigFromEnvironment = function () {
diff --git a/packages/pg/lib/defaults.js b/packages/pg/lib/defaults.js
index 015909dcd..673696f79 100644
--- a/packages/pg/lib/defaults.js
+++ b/packages/pg/lib/defaults.js
@@ -1,11 +1,18 @@
 'use strict'
 
+let user
+try {
+  user = process.platform === 'win32' ? process.env.USERNAME : process.env.USER
+} catch {
+  // ignore, e.g., Deno without --allow-env
+}
+
 module.exports = {
   // database host. defaults to localhost
   host: 'localhost',
 
   // database user's name
-  user: process.platform === 'win32' ? process.env.USERNAME : process.env.USER,
+  user,
 
   // name of database to connect
   database: undefined,
diff --git a/packages/pg/lib/index.js b/packages/pg/lib/index.js
index 5bd73385b..e8b746149 100644
--- a/packages/pg/lib/index.js
+++ b/packages/pg/lib/index.js
@@ -34,31 +34,40 @@ const PG = function (clientConstructor) {
   this.utils = utils
 }
 
-if (typeof process.env.NODE_PG_FORCE_NATIVE !== 'undefined') {
-  module.exports = new PG(require('./native'))
-} else {
-  module.exports = new PG(Client)
+let clientConstructor = Client
 
-  // lazy require native module...the native module may not have installed
-  Object.defineProperty(module.exports, 'native', {
-    configurable: true,
-    enumerable: false,
-    get() {
-      let native = null
-      try {
-        native = new PG(require('./native'))
-      } catch (err) {
-        if (err.code !== 'MODULE_NOT_FOUND') {
-          throw err
-        }
+let forceNative = false
+try {
+  forceNative = !!process.env.NODE_PG_FORCE_NATIVE
+} catch {
+  // ignore, e.g., Deno without --allow-env
+}
+
+if (forceNative) {
+  clientConstructor = require('./native')
+}
+
+module.exports = new PG(clientConstructor)
+
+// lazy require native module...the native module may not have installed
+Object.defineProperty(module.exports, 'native', {
+  configurable: true,
+  enumerable: false,
+  get() {
+    let native = null
+    try {
+      native = new PG(require('./native'))
+    } catch (err) {
+      if (err.code !== 'MODULE_NOT_FOUND') {
+        throw err
       }
+    }
 
-      // overwrite module.exports.native so that getter is never called again
-      Object.defineProperty(module.exports, 'native', {
-        value: native,
-      })
+    // overwrite module.exports.native so that getter is never called again
+    Object.defineProperty(module.exports, 'native', {
+      value: native,
+    })
 
-      return native
-    },
-  })
-}
+    return native
+  },
+})