diff --git a/gradle.properties b/gradle.properties
index 4e033d05..4ef9f0bc 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1,10 +1,12 @@
 kotlin.code.style=official
 
 
-kotlinVersion=2.0.10
+
+kotlinVersion=1.9.25
 
 kotlinxDateTimeVersion=0.5.0
 jsJodaTimeZoneVersion=2.3.0
+# Coroutines 1.9 (currently RC) requires Kotlin 2.0
 coroutinesVersion=1.8.1
 
 # 0.3.10 uses Kotlin 2.0.0