diff --git a/CHANGELOG b/CHANGELOG
index fc0f2b5e..a491a9b8 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,5 +1,11 @@
 # Change Log of ARCADE
 
+## [2.5.0] - 2019-05-23
+### NEW
+*   ARCADE sends a [0 1 0] eventmarker sequence at beginning and and of a
+    session. This can be used to synchronize different recording systems, e.g.
+    Eyelink and TDT Sys3.
+
 ## [2.5.0b3] - 2019-05-17
 ### NEW
 *   NidaqServer 1.0.10.6: support for PCIe-6323