diff --git a/server/TracyEvent.hpp b/server/TracyEvent.hpp
index 00ca919e..33e81f24 100644
--- a/server/TracyEvent.hpp
+++ b/server/TracyEvent.hpp
@@ -542,6 +542,7 @@ struct ContextSwitchData
         Fiber = 99,
         NoState = 100,
 
+        // See KWAIT_REASON in the WDK's wdm.h
         Win32_Executive         = 0 ,
         Win32_FreePage          = 1 ,
         Win32_PageIn            = 2 ,