diff --git a/README.md b/README.md
index fa25906..1267d4a 100644
--- a/README.md
+++ b/README.md
@@ -215,6 +215,12 @@ Append to `config.txt`:
 enable_uart=1
 ```
 
+On Raspberry Pi 3's you'll also need to append:
+
+```
+core_freq=250
+```
+
 Optionally set up a cronjob:
 
 ```