diff --git a/boards/sltb001a/doc.txt b/boards/sltb001a/doc.txt
index 0f0681451f..75674dffa0 100644
--- a/boards/sltb001a/doc.txt
+++ b/boards/sltb001a/doc.txt
@@ -118,7 +118,8 @@ expects data from the MCU with the same settings.
 
 ### Clock selection
 There are several clock sources that are available for the different
-peripherals. You are advised to read [AN0004](https://www.silabs.com/Support%20Documents/TechnicalDocs/AN0004.pdf)
+peripherals. You are advised to read [AN0004.1]
+(https://www.silabs.com/documents/public/application-notes/an0004.1-efm32-cmu.pdf)
 to get familiar with the different clocks.
 
 | Source | Internal | Speed      | Comments                           |