diff --git a/env_loc.js b/env_loc.js
index 3827896..c73e1ac 100644
--- a/env_loc.js
+++ b/env_loc.js
@@ -39,7 +39,9 @@ const existingEnv = fs.existsSync('./env_loc.gitomit.sfomit.json') ? require(pat
 
 const baseEnv = Object.assign({}, paramDefaults, defaultEnv, existingEnv)
 
-const askParamValues = (keys) =>
+const isEmptyValue = (value) => value === '' || value === undefined || value === null
+
+const askKeyValues = (keys) =>
   new Promise((resolve) => {
     if (!keys.length || !process.stdin.isTTY) {
       resolve({})
@@ -61,7 +63,7 @@ const askParamValues = (keys) =>
       }
 
       const key = keys[index]
-      rl.question(`Input value for "${key}" (Enter for empty): `, (answer) => {
+      rl.question(`Input value for "${key}" (Enter to keep empty): `, (answer) => {
         values[key] = answer === '' ? '' : answer
         index += 1
         askNext()
@@ -72,7 +74,8 @@ const askParamValues = (keys) =>
   })
 
 const main = async () => {
-  const inputValues = await askParamValues(params)
+  const keysToPrompt = Object.keys(baseEnv).filter((key) => isEmptyValue(baseEnv[key]))
+  const inputValues = await askKeyValues(keysToPrompt)
   const localEnv = Object.assign({}, baseEnv, inputValues)
 
   fs.writeFileSync(path.resolve('./env_loc.gitomit.sfomit.json'), JSON.stringify(localEnv, null, 2), 'utf8')