diff --git a/secretk/src/commonMain/kotlin/io/eqoty/secretk/client/RestClient.kt b/secretk/src/commonMain/kotlin/io/eqoty/secretk/client/RestClient.kt
index 99b128d..3de33bc 100644
--- a/secretk/src/commonMain/kotlin/io/eqoty/secretk/client/RestClient.kt
+++ b/secretk/src/commonMain/kotlin/io/eqoty/secretk/client/RestClient.kt
@@ -205,7 +205,7 @@ internal class RestClient(
     suspend fun decryptDataField(msg: MsgProto, nonce: UByteArray?): UByteArray {
         val dataField = when (msg) {
             is MsgExecuteContractResponseProto -> {
-                msg.data.toUByteArray()
+                msg.data?.toUByteArray() ?: UByteArray(0) { 0u }
             }
 
             is MsgInstantiateContractResponseProto -> {
diff --git a/secretk/src/commonMain/kotlin/io/eqoty/secretk/types/proto/MsgDataProto.kt b/secretk/src/commonMain/kotlin/io/eqoty/secretk/types/proto/MsgDataProto.kt
index df91a34..0d6edb6 100644
--- a/secretk/src/commonMain/kotlin/io/eqoty/secretk/types/proto/MsgDataProto.kt
+++ b/secretk/src/commonMain/kotlin/io/eqoty/secretk/types/proto/MsgDataProto.kt
@@ -11,19 +11,19 @@ import kotlinx.serialization.protobuf.ProtoNumber
 @kotlinx.serialization.Serializable
 class MsgDataProto(
     @ProtoNumber(1) val msgType: String = "",
-    @ProtoNumber(2) val data: ByteArray,
+    @ProtoNumber(2) val data: ByteArray? = null,
 ) : MsgProto() {
     fun toMsgResponseType(): MsgProto = when (msgType) {
         "/secret.compute.v1beta1.MsgInstantiateContract" -> {
-            ProtoBuf.decodeFromByteArray(data) as MsgInstantiateContractResponseProto
+            ProtoBuf.decodeFromByteArray(data ?: byteArrayOf()) as MsgInstantiateContractResponseProto
         }
 
         "/secret.compute.v1beta1.MsgExecuteContract" -> {
-            ProtoBuf.decodeFromByteArray(data) as MsgExecuteContractResponseProto
+            ProtoBuf.decodeFromByteArray(data ?: byteArrayOf()) as MsgExecuteContractResponseProto
         }
 
         "/secret.compute.v1beta1.MsgStoreCode" -> {
-            ProtoBuf.decodeFromByteArray(data) as MsgStoreCodeResponseProto
+            ProtoBuf.decodeFromByteArray(data ?: byteArrayOf()) as MsgStoreCodeResponseProto
         }
 
         else -> throw UnsupportedOperationException("calling toMsg() on an Any proto with typeUrl:${msgType} is not supported")
diff --git a/secretk/src/commonMain/kotlin/io/eqoty/secretk/types/proto/MsgExecuteContractResponseProto.kt b/secretk/src/commonMain/kotlin/io/eqoty/secretk/types/proto/MsgExecuteContractResponseProto.kt
index 9c70d13..4a4920c 100644
--- a/secretk/src/commonMain/kotlin/io/eqoty/secretk/types/proto/MsgExecuteContractResponseProto.kt
+++ b/secretk/src/commonMain/kotlin/io/eqoty/secretk/types/proto/MsgExecuteContractResponseProto.kt
@@ -8,5 +8,5 @@ import kotlinx.serialization.protobuf.ProtoNumber
  */
 @kotlinx.serialization.Serializable
 class MsgExecuteContractResponseProto(
-    @ProtoNumber(1) val data: ByteArray
+    @ProtoNumber(1) val data: ByteArray? = null
 ) : MsgProto()
\ No newline at end of file