diff --git a/sora-android-sdk/src/main/kotlin/jp/shiguredo/sora/sdk/channel/signaling/message/Catalog.kt b/sora-android-sdk/src/main/kotlin/jp/shiguredo/sora/sdk/channel/signaling/message/Catalog.kt
index cca512e5..366f67eb 100644
--- a/sora-android-sdk/src/main/kotlin/jp/shiguredo/sora/sdk/channel/signaling/message/Catalog.kt
+++ b/sora-android-sdk/src/main/kotlin/jp/shiguredo/sora/sdk/channel/signaling/message/Catalog.kt
@@ -111,18 +111,18 @@ data class RedirectMessage(
 data class OfferMessage(
     @SerializedName("type") val type: String = "offer",
     @SerializedName("sdp") val sdp: String,
-    @SerializedName("version") val version: String,
+    @SerializedName("version") val version: String? = null,
 
-    @SerializedName("multistream") val multistream: Boolean,
+    @SerializedName("multistream") val multistream: Boolean? = null,
     @SerializedName("simulcast") val simulcast: Boolean,
-    @SerializedName("simulcast_multicodec") val simulcastMulticodec: Boolean,
-    @SerializedName("spotlight") val spotlight: Boolean,
+    @SerializedName("simulcast_multicodec") val simulcastMulticodec: Boolean? = null,
+    @SerializedName("spotlight") val spotlight: Boolean? = null,
 
-    @SerializedName("channel_id") val channelId: String,
+    @SerializedName("channel_id") val channelId: String? = null,
     @SerializedName("client_id") val clientId: String,
     @SerializedName("bundle_id") val bundleId: String? = null,
     @SerializedName("connection_id") val connectionId: String,
-    @SerializedName("session_id") val sessionId: String?,
+    @SerializedName("session_id") val sessionId: String? = null,
 
     @SerializedName("metadata") val metadata: Any?,
     @SerializedName("config") val config: OfferConfig? = null,
@@ -130,12 +130,12 @@ data class OfferMessage(
     @SerializedName("encodings") val encodings: List<Encoding>?,
     @SerializedName("data_channels") val dataChannels: List<Map<String, Any>>? = null,
 
-    @SerializedName("audio") val audio: Boolean?,
-    @SerializedName("audio_codec_type") val audioCodecType: String?,
-    @SerializedName("audio_bit_rate") val audioBitRate: Int?,
-    @SerializedName("video") val video: Boolean?,
-    @SerializedName("video_codec_type") val videoCodecType: String?,
-    @SerializedName("video_bit_rate") val videoBitRate: Int?,
+    @SerializedName("audio") val audio: Boolean? = null,
+    @SerializedName("audio_codec_type") val audioCodecType: String? = null,
+    @SerializedName("audio_bit_rate") val audioBitRate: Int? = null,
+    @SerializedName("video") val video: Boolean? = null,
+    @SerializedName("video_codec_type") val videoCodecType: String? = null,
+    @SerializedName("video_bit_rate") val videoBitRate: Int? = null,
 )
 
 data class SwitchedMessage(