diff --git a/tgbotapi.core/src/commonMain/kotlin/dev/inmo/tgbotapi/types/buttons/KeyboardButtonRequestChat.kt b/tgbotapi.core/src/commonMain/kotlin/dev/inmo/tgbotapi/types/buttons/KeyboardButtonRequestChat.kt
index e423daeb57..a78ed9bb78 100644
--- a/tgbotapi.core/src/commonMain/kotlin/dev/inmo/tgbotapi/types/buttons/KeyboardButtonRequestChat.kt
+++ b/tgbotapi.core/src/commonMain/kotlin/dev/inmo/tgbotapi/types/buttons/KeyboardButtonRequestChat.kt
@@ -33,6 +33,6 @@ data class KeyboardButtonRequestChat(
     @SerialName(botAdministratorRightsField)
     val botRightsInChat: ChatAdministratorRights? = null,
     @SerialName(botIsMemberField)
-    val botIsMember: Boolean = false
+    val botIsMember: Boolean? = null
 )
 
diff --git a/tgbotapi.utils/src/commonMain/kotlin/dev/inmo/tgbotapi/extensions/utils/types/buttons/ReplyKeyboardBuilder.kt b/tgbotapi.utils/src/commonMain/kotlin/dev/inmo/tgbotapi/extensions/utils/types/buttons/ReplyKeyboardBuilder.kt
index 3b8cce77cf..a41a2cb0f1 100644
--- a/tgbotapi.utils/src/commonMain/kotlin/dev/inmo/tgbotapi/extensions/utils/types/buttons/ReplyKeyboardBuilder.kt
+++ b/tgbotapi.utils/src/commonMain/kotlin/dev/inmo/tgbotapi/extensions/utils/types/buttons/ReplyKeyboardBuilder.kt
@@ -235,7 +235,7 @@ inline fun ReplyKeyboardRowBuilder.requestChatButton(
     ownedBy: Boolean? = null,
     userRightsInChat: ChatAdministratorRights? = null,
     botRightsInChat: ChatAdministratorRights? = null,
-    botIsMember: Boolean = false
+    botIsMember: Boolean? = null
 ) = requestChatButton(
     text,
     KeyboardButtonRequestChat(