diff --git a/README.md b/README.md
index 53c38fd..5ed1d11 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # replace-action
 
-This lightweight action replaces substrings in files. It is useful for CI process when you needto update your configs depending on the previous steps results.
+This lightweight action replaces substrings in files. It is useful for CI process when you need to update your configs depending on the previous steps results.
 
 # Usage
 
@@ -11,8 +11,9 @@ See [action.yml](action.yml)
 uses: datamonsters/replace-action
 with:
   files: 'path1/file1,path2/file2'
-  replacements: 'foo=bar,$FOO=Bar_Value'
+  replacements: 'foo=bar,@FOO=Bar_Value'
 ```
+As the replacement is using regular expression, you should avoid 'special' characters which might be misinterpreted in the RegEx context.
 
 # Example
 
@@ -73,4 +74,4 @@ jobs:
 
 # License
 
-The scripts and documentation in this project are released under the [MIT License](LICENSE)
\ No newline at end of file
+The scripts and documentation in this project are released under the [MIT License](LICENSE)
diff --git a/index.js b/index.js
index 493e581..bbfb427 100755
--- a/index.js
+++ b/index.js
@@ -22,7 +22,8 @@ try {
           var kv = vars[i].split('=')
           var key = kv[0]
           var value = kv[1]
-          result = result.replace(key, value)
+          var regx = new RegExp(key, 'g')
+          result = result.replace(regx, value)
         }
         console.log('file2: '+filename)
         fs.writeFile(filename, result, 'utf8', function (err) {