diff --git a/application/src/test/java/org/thingsboard/server/controller/BaseDeviceProfileControllerTest.java b/application/src/test/java/org/thingsboard/server/controller/BaseDeviceProfileControllerTest.java
index 937283b31c..ea5a6dbf86 100644
--- a/application/src/test/java/org/thingsboard/server/controller/BaseDeviceProfileControllerTest.java
+++ b/application/src/test/java/org/thingsboard/server/controller/BaseDeviceProfileControllerTest.java
@@ -779,7 +779,7 @@ public abstract class BaseDeviceProfileControllerTest extends AbstractController
                 "\n" +
                 "message RpcRequestMsg {\n" +
                 "  optional int32 requestId = 2;\n" +
-                "  repeated string params = 3;\n" +
+                "  optional string params = 3;\n" +
                 "  \n" +
                 "}", "[Transport Configuration] invalid rpc request proto schema provided! RpcRequestMsg message should always contains 3 fields: method, requestId and params!");
     }
@@ -793,7 +793,7 @@ public abstract class BaseDeviceProfileControllerTest extends AbstractController
                 "message RpcRequestMsg {\n" +
                 "  optional string methodName = 1;\n" +
                 "  optional int32 requestId = 2;\n" +
-                "  repeated string params = 3;\n" +
+                "  optional string params = 3;\n" +
                 "  \n" +
                 "}", "[Transport Configuration] invalid rpc request proto schema provided! Failed to get field descriptor for field: method!");
     }
@@ -807,7 +807,7 @@ public abstract class BaseDeviceProfileControllerTest extends AbstractController
                 "message RpcRequestMsg {\n" +
                 "  optional string method = 1;\n" +
                 "  optional int32 requestIdentifier = 2;\n" +
-                "  repeated string params = 3;\n" +
+                "  optional string params = 3;\n" +
                 "  \n" +
                 "}", "[Transport Configuration] invalid rpc request proto schema provided! Failed to get field descriptor for field: requestId!");
     }
@@ -821,7 +821,7 @@ public abstract class BaseDeviceProfileControllerTest extends AbstractController
                 "message RpcRequestMsg {\n" +
                 "  optional string method = 1;\n" +
                 "  optional int32 requestId = 2;\n" +
-                "  repeated string parameters = 3;\n" +
+                "  optional string parameters = 3;\n" +
                 "  \n" +
                 "}", "[Transport Configuration] invalid rpc request proto schema provided! Failed to get field descriptor for field: params!");
     }
diff --git a/application/src/test/java/org/thingsboard/server/transport/coap/rpc/AbstractCoapServerSideRpcProtoIntegrationTest.java b/application/src/test/java/org/thingsboard/server/transport/coap/rpc/AbstractCoapServerSideRpcProtoIntegrationTest.java
index 544090d7c8..ad5cf78bc3 100644
--- a/application/src/test/java/org/thingsboard/server/transport/coap/rpc/AbstractCoapServerSideRpcProtoIntegrationTest.java
+++ b/application/src/test/java/org/thingsboard/server/transport/coap/rpc/AbstractCoapServerSideRpcProtoIntegrationTest.java
@@ -58,13 +58,13 @@ public abstract class AbstractCoapServerSideRpcProtoIntegrationTest extends Abst
             "package rpc;\n" +
             "\n" +
             "message RpcRequestMsg {\n" +
-            "  string method = 1;\n" +
-            "  int32 requestId = 2;\n" +
+            "  optional string method = 1;\n" +
+            "  optional int32 requestId = 2;\n" +
             "  Params params = 3;\n" +
             "\n" +
             "  message Params {\n" +
-            "      string pin = 1;\n" +
-            "      int32 value = 2;\n" +
+            "      optional string pin = 1;\n" +
+            "      optional int32 value = 2;\n" +
             "   }\n" +
             "}";
 
diff --git a/application/src/test/java/org/thingsboard/server/transport/mqtt/rpc/AbstractMqttServerSideRpcProtoIntegrationTest.java b/application/src/test/java/org/thingsboard/server/transport/mqtt/rpc/AbstractMqttServerSideRpcProtoIntegrationTest.java
index eea800fb0e..cf9ae499c4 100644
--- a/application/src/test/java/org/thingsboard/server/transport/mqtt/rpc/AbstractMqttServerSideRpcProtoIntegrationTest.java
+++ b/application/src/test/java/org/thingsboard/server/transport/mqtt/rpc/AbstractMqttServerSideRpcProtoIntegrationTest.java
@@ -56,13 +56,13 @@ public abstract class AbstractMqttServerSideRpcProtoIntegrationTest extends Abst
             "package rpc;\n" +
             "\n" +
             "message RpcRequestMsg {\n" +
-            "  string method = 1;\n" +
-            "  int32 requestId = 2;\n" +
+            "  optional string method = 1;\n" +
+            "  optional int32 requestId = 2;\n" +
             "  Params params = 3;\n" +
             "\n" +
             "  message Params {\n" +
-            "      string pin = 1;\n" +
-            "      int32 value = 2;\n" +
+            "      optional string pin = 1;\n" +
+            "      optional int32 value = 2;\n" +
             "   }\n" +
             "}";
 
diff --git a/common/data/src/main/java/org/thingsboard/server/common/data/device/profile/ProtoTransportPayloadConfiguration.java b/common/data/src/main/java/org/thingsboard/server/common/data/device/profile/ProtoTransportPayloadConfiguration.java
index aed3d480ef..d3836a35a0 100644
--- a/common/data/src/main/java/org/thingsboard/server/common/data/device/profile/ProtoTransportPayloadConfiguration.java
+++ b/common/data/src/main/java/org/thingsboard/server/common/data/device/profile/ProtoTransportPayloadConfiguration.java
@@ -83,7 +83,7 @@ public class ProtoTransportPayloadConfiguration implements TransportPayloadTypeC
                     "package rpc;\n" +
                     "\n" +
                     "message RpcResponseMsg {\n" +
-                    "  string payload = 1;\n" +
+                    "  optional string payload = 1;\n" +
                     "}";
         }
     }
@@ -96,9 +96,9 @@ public class ProtoTransportPayloadConfiguration implements TransportPayloadTypeC
                     "package rpc;\n" +
                     "\n" +
                     "message RpcRequestMsg {\n" +
-                    "  string method = 1;\n" +
-                    "  int32 requestId = 2;\n" +
-                    "  string params = 3;\n" +
+                    "  optional string method = 1;\n" +
+                    "  optional int32 requestId = 2;\n" +
+                    "  optional string params = 3;\n" +
                     "}";
         }
     }
diff --git a/common/transport/coap/src/main/java/org/thingsboard/server/transport/coap/adaptors/ProtoCoapAdaptor.java b/common/transport/coap/src/main/java/org/thingsboard/server/transport/coap/adaptors/ProtoCoapAdaptor.java
index 330c4cc579..20e72fb023 100644
--- a/common/transport/coap/src/main/java/org/thingsboard/server/transport/coap/adaptors/ProtoCoapAdaptor.java
+++ b/common/transport/coap/src/main/java/org/thingsboard/server/transport/coap/adaptors/ProtoCoapAdaptor.java
@@ -16,7 +16,6 @@
 package org.thingsboard.server.transport.coap.adaptors;
 
 import com.google.gson.JsonElement;
-import com.google.gson.JsonObject;
 import com.google.gson.JsonParser;
 import com.google.protobuf.Descriptors;
 import com.google.protobuf.DynamicMessage;
diff --git a/common/transport/transport-api/src/main/java/org/thingsboard/server/common/transport/adaptor/ProtoConverter.java b/common/transport/transport-api/src/main/java/org/thingsboard/server/common/transport/adaptor/ProtoConverter.java
index 620728cda4..39d4db069e 100644
--- a/common/transport/transport-api/src/main/java/org/thingsboard/server/common/transport/adaptor/ProtoConverter.java
+++ b/common/transport/transport-api/src/main/java/org/thingsboard/server/common/transport/adaptor/ProtoConverter.java
@@ -175,7 +175,7 @@ public class ProtoConverter {
     }
 
     public static byte[] convertToRpcRequest(TransportProtos.ToDeviceRpcRequestMsg toDeviceRpcRequestMsg, DynamicMessage.Builder rpcRequestDynamicMessageBuilder) throws AdaptorException {
-        rpcRequestDynamicMessageBuilder.clear();
+        rpcRequestDynamicMessageBuilder = rpcRequestDynamicMessageBuilder.getDefaultInstanceForType().newBuilderForType();
         JsonObject rpcRequestJson = new JsonObject();
         rpcRequestJson.addProperty("method", toDeviceRpcRequestMsg.getMethodName());
         rpcRequestJson.addProperty("requestId", toDeviceRpcRequestMsg.getRequestId());