diff --git a/projector-client-web/src/main/kotlin/org/jetbrains/projector/client/web/state/ClientState.kt b/projector-client-web/src/main/kotlin/org/jetbrains/projector/client/web/state/ClientState.kt
index 47caba7fd..945f71c57 100644
--- a/projector-client-web/src/main/kotlin/org/jetbrains/projector/client/web/state/ClientState.kt
+++ b/projector-client-web/src/main/kotlin/org/jetbrains/projector/client/web/state/ClientState.kt
@@ -49,10 +49,7 @@ import org.jetbrains.projector.common.protocol.MessageDecoder
 import org.jetbrains.projector.common.protocol.MessageEncoder
 import org.jetbrains.projector.common.protocol.compress.MessageCompressor
 import org.jetbrains.projector.common.protocol.compress.MessageDecompressor
-import org.jetbrains.projector.common.protocol.handshake.COMMON_VERSION
-import org.jetbrains.projector.common.protocol.handshake.ToClientHandshakeFailureEvent
-import org.jetbrains.projector.common.protocol.handshake.ToClientHandshakeSuccessEvent
-import org.jetbrains.projector.common.protocol.handshake.ToServerHandshakeEvent
+import org.jetbrains.projector.common.protocol.handshake.*
 import org.jetbrains.projector.common.protocol.toClient.ServerDrawCommandsEvent
 import org.jetbrains.projector.common.protocol.toClient.ToClientMessageDecoder
 import org.jetbrains.projector.common.protocol.toServer.*
@@ -133,6 +130,7 @@ sealed class ClientState {
         val handshakeEvent = with(SupportedTypesProvider) {
           ToServerHandshakeEvent(
             commonVersion = COMMON_VERSION,
+            commonVersionId = commonVersionList.indexOf(COMMON_VERSION),
             token = ParamsProvider.HANDSHAKE_TOKEN,
             initialSize = windowSizeController.currentSize,
             supportedToClientCompressions = supportedToClientDecompressors.map(MessageDecompressor<*>::compressionType),
diff --git a/projector-common/src/commonMain/kotlin/org/jetbrains/projector/common/protocol/handshake/Constant.kt b/projector-common/src/commonMain/kotlin/org/jetbrains/projector/common/protocol/handshake/Constant.kt
index 87d9d3efd..57698772a 100644
--- a/projector-common/src/commonMain/kotlin/org/jetbrains/projector/common/protocol/handshake/Constant.kt
+++ b/projector-common/src/commonMain/kotlin/org/jetbrains/projector/common/protocol/handshake/Constant.kt
@@ -31,3 +31,8 @@ import org.jetbrains.projector.common.protocol.toServer.ClientEvent
 val COMMON_VERSION = listOf(ServerEvent.serializer(), ClientEvent.serializer())
   .map { it.list.descriptor.compatibilityHash }
   .reduce(Int::xor)
+
+// Don't change order here: it's used to obtain readable "human id"
+val commonVersionList = listOf(
+  -1663032476
+)
diff --git a/projector-common/src/commonMain/kotlin/org/jetbrains/projector/common/protocol/handshake/ToServerHandshakeEvent.kt b/projector-common/src/commonMain/kotlin/org/jetbrains/projector/common/protocol/handshake/ToServerHandshakeEvent.kt
index 1b834765d..1244a26d0 100644
--- a/projector-common/src/commonMain/kotlin/org/jetbrains/projector/common/protocol/handshake/ToServerHandshakeEvent.kt
+++ b/projector-common/src/commonMain/kotlin/org/jetbrains/projector/common/protocol/handshake/ToServerHandshakeEvent.kt
@@ -29,6 +29,7 @@ import org.jetbrains.projector.common.protocol.data.CommonIntSize
 @Serializable
 data class ToServerHandshakeEvent(
   val commonVersion: Int,
+  val commonVersionId: Int,
   val token: String? = null,
   val initialSize: CommonIntSize,
   val supportedToClientCompressions: List<CompressionType>,
diff --git a/projector-common/src/commonTest/kotlin/org/jetbrains/projector/common/protocol/CommonVersionPresenceTest.kt b/projector-common/src/commonTest/kotlin/org/jetbrains/projector/common/protocol/CommonVersionPresenceTest.kt
new file mode 100644
index 000000000..58520ad3e
--- /dev/null
+++ b/projector-common/src/commonTest/kotlin/org/jetbrains/projector/common/protocol/CommonVersionPresenceTest.kt
@@ -0,0 +1,47 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019-2020 JetBrains s.r.o.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package org.jetbrains.projector.common.protocol
+
+import org.jetbrains.projector.common.protocol.handshake.COMMON_VERSION
+import org.jetbrains.projector.common.protocol.handshake.commonVersionList
+import kotlin.test.Test
+import kotlin.test.assertTrue
+
+class CommonVersionPresenceTest {
+
+  @Test
+  fun commonVersionListShouldContainCurrentCommonVersion() {
+    assertTrue(
+      COMMON_VERSION in commonVersionList,
+      """
+        |Current common version of protocol should be in `commonVersionList`.
+        |It seems that protocol has been updated.
+        |Please append the current COMMON_VERSION to the commonVersionList as the last element.
+        |Current values:
+        |COMMON_VERSION = $COMMON_VERSION
+        |commonVersionList = $commonVersionList
+      """.trimMargin()
+    )
+  }
+}