diff --git a/build.gradle.kts b/build.gradle.kts
index 532c923..dbd45c9 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -51,7 +51,7 @@ configure(projects) {
         implementation("org.jetbrains.kotlinx:kotlinx-coroutines-jdk8:$coroutinesVersion")
         implementation("org.jetbrains.kotlinx:kotlinx-coroutines-test:$coroutinesVersion")
 
-        val kotlinSerializationVersion = "1.2.1"
+        val kotlinSerializationVersion = "1.1.0"
         implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:$kotlinSerializationVersion")
         implementation("org.jetbrains.kotlinx:kotlinx-serialization-protobuf:$kotlinSerializationVersion")