diff --git a/registry.txt b/registry.txt
index e4d3feb7..74467ca1 100644
--- a/registry.txt
+++ b/registry.txt
@@ -5595,3 +5595,4 @@ https://github.com/stm32duino/STM32LoRaWAN.git|Contributed|STM32duinoLoRaWAN
 https://github.com/firechip/Firechip_Analog_Devices_MAX14521E_Arduino_Library.git|Contributed|FC0001614614
 https://github.com/bolderflight/hg4930.git|Contributed|Bolder Flight Systems Honeywell HG4930
 https://github.com/107-systems/107-Arduino-UniqueId.git|Contributed|107-Arduino-UniqueId
+https://github.com/107-systems/107-Arduino-CriticalSection.git|Contributed|107-Arduino-CriticalSection