diff --git a/src/commonMain/kotlin/io/github/oshai/kotlinlogging/KLoggingEventBuilder.kt b/src/commonMain/kotlin/io/github/oshai/kotlinlogging/KLoggingEventBuilder.kt
index 98d79b6d..c1d77428 100644
--- a/src/commonMain/kotlin/io/github/oshai/kotlinlogging/KLoggingEventBuilder.kt
+++ b/src/commonMain/kotlin/io/github/oshai/kotlinlogging/KLoggingEventBuilder.kt
@@ -3,5 +3,5 @@ package io.github.oshai.kotlinlogging
 public class KLoggingEventBuilder {
   public var message: String? = null
   public var cause: Throwable? = null
-  public var payload: Map<String, Any>? = null
+  public var payload: Map<String, Any?>? = null
 }
diff --git a/src/directMain/kotlin/io/github/oshai/kotlinlogging/KLoggingEvent.kt b/src/directMain/kotlin/io/github/oshai/kotlinlogging/KLoggingEvent.kt
index 427f5396..a06afbfb 100644
--- a/src/directMain/kotlin/io/github/oshai/kotlinlogging/KLoggingEvent.kt
+++ b/src/directMain/kotlin/io/github/oshai/kotlinlogging/KLoggingEvent.kt
@@ -6,7 +6,7 @@ public data class KLoggingEvent(
   public val loggerName: String,
   public val message: String? = null,
   public val cause: Throwable? = null,
-  public val payload: Map<String, Any>? = null,
+  public val payload: Map<String, Any?>? = null,
 ) {
   public constructor(
     level: Level,