diff --git a/CMakeLists.txt b/CMakeLists.txt
index 49ac5ff9e..dd75bf1ee 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -170,7 +170,7 @@ IF( NOT SIO_FOUND )
   include(FetchContent)
   FetchContent_Declare(sio_extern
   GIT_REPOSITORY https://github.com/iLCSoft/SIO.git
-  GIT_TAG master
+  GIT_TAG v00-01
   GIT_SHALLOW 1
 #  FIND_PACKAGE_ARGS
 )