diff --git a/lib/main.js b/lib/main.js
index c9c18b1..2fcedbd 100644
--- a/lib/main.js
+++ b/lib/main.js
@@ -8,7 +8,7 @@ var dotenvExpand = function (config) {
       var key = match.replace(/\$|{|}/g, '')
 
       // process.env value 'wins' over .env file's value
-      var variable = process.env[key] || config.parsed[key] || ''
+      var variable = process.env.hasOwnProperty(key) ? process.env[key] : (config.parsed[key] || '')
 
       // Resolve recursive interpolations
       variable = interpolate(variable)
@@ -20,7 +20,7 @@ var dotenvExpand = function (config) {
   }
 
   for (var configKey in config.parsed) {
-    var value = process.env[configKey] || config.parsed[configKey]
+    var value = process.env.hasOwnProperty(configKey) ? process.env[configKey] : config.parsed[configKey]
 
     if (config.parsed[configKey].substring(0, 2) === '\\$') {
       config.parsed[configKey] = value.substring(1)