diff --git a/ADVANCED_README.md b/ADVANCED_README.md
index 8bf0d0d9..41249ee9 100644
--- a/ADVANCED_README.md
+++ b/ADVANCED_README.md
@@ -502,7 +502,7 @@ Value passed is in megaoctets. Internally it uses the V8 flag `--max-old-space-s
 
 CLI:
 ```bash
-$ pm2 start big-array.js --max-memory-restart 20
+$ pm2 start big-array.js --max-memory-restart 20M
 ```
 
 JSON:
@@ -514,6 +514,8 @@ JSON:
 }
 ```
 
+Units can be K(ilobyte), M(egabyte), G(igabyte).
+
 <a name="a7"/>
 ## Monitoring CPU/Memory usage