diff --git a/README.md b/README.md
index a87831d0..7ccff29a 100644
--- a/README.md
+++ b/README.md
@@ -152,7 +152,7 @@ In example, to replace inject the value of `process.env.NODE_ENV`:
 
 ```js
 autoPreprocess({
-  replace: [['process.env.NODE_ENV', JSON.stringify(process.env.NODE_ENV)]],
+  replace: [[/process\.env\.NODE_ENV/g, JSON.stringify(process.env.NODE_ENV)]],
 });
 ```
 
diff --git a/docs/preprocessing.md b/docs/preprocessing.md
index 6f88cca9..1f4d61cc 100644
--- a/docs/preprocessing.md
+++ b/docs/preprocessing.md
@@ -484,3 +484,5 @@ And the result, with a `NODE_ENV = 'production'` would be:
   <h1>Production environment!</h1>
 {/if}
 ```
+
+> Note: a string can be used instead of a `RegExp`, but only a single occurence of it will change, as per the default behavior of `String.prototype.replace`.