diff --git a/consensus/ibft/src/test/java/tech/pegasys/pantheon/consensus/ibft/statemachine/RoundChangeManagerTest.java b/consensus/ibft/src/test/java/tech/pegasys/pantheon/consensus/ibft/statemachine/RoundChangeManagerTest.java
index 8633004524..490e77a22c 100644
--- a/consensus/ibft/src/test/java/tech/pegasys/pantheon/consensus/ibft/statemachine/RoundChangeManagerTest.java
+++ b/consensus/ibft/src/test/java/tech/pegasys/pantheon/consensus/ibft/statemachine/RoundChangeManagerTest.java
@@ -27,6 +27,7 @@ import tech.pegasys.pantheon.consensus.ibft.ibftmessagedata.ProposalPayload;
 import tech.pegasys.pantheon.consensus.ibft.ibftmessagedata.RoundChangePayload;
 import tech.pegasys.pantheon.consensus.ibft.ibftmessagedata.SignedData;
 import tech.pegasys.pantheon.consensus.ibft.validation.MessageValidator;
+import tech.pegasys.pantheon.consensus.ibft.validation.RoundChangeMessageValidator;
 import tech.pegasys.pantheon.crypto.SECP256K1.KeyPair;
 import tech.pegasys.pantheon.ethereum.ProtocolContext;
 import tech.pegasys.pantheon.ethereum.chain.MutableBlockchain;
@@ -39,13 +40,11 @@ import tech.pegasys.pantheon.ethereum.mainnet.BlockHeaderValidator;
 
 import java.util.Collections;
 import java.util.List;
-import java.util.Map;
 import java.util.Optional;
 import java.util.stream.Collectors;
 
 import com.google.common.base.Preconditions;
 import com.google.common.collect.Lists;
-import com.google.common.collect.Maps;
 import org.junit.Before;
 import org.junit.Test;
 
@@ -80,39 +79,41 @@ public class RoundChangeManagerTest {
     when(headerValidator.validateHeader(any(), any(), any(), any())).thenReturn(true);
     BlockHeader parentHeader = mock(BlockHeader.class);
 
-    Map<ConsensusRoundIdentifier, MessageValidator> messageValidators = Maps.newHashMap();
-
-    messageValidators.put(
-        ri1,
-        new MessageValidator(
-            validators,
-            Util.publicKeyToAddress(proposerKey.getPublicKey()),
-            ri1,
-            headerValidator,
-            protocolContext,
-            parentHeader));
-
-    messageValidators.put(
-        ri2,
-        new MessageValidator(
-            validators,
-            Util.publicKeyToAddress(validator1Key.getPublicKey()),
-            ri2,
-            headerValidator,
-            protocolContext,
-            parentHeader));
-
-    messageValidators.put(
-        ri3,
-        new MessageValidator(
-            validators,
-            Util.publicKeyToAddress(validator2Key.getPublicKey()),
-            ri3,
-            headerValidator,
-            protocolContext,
-            parentHeader));
-
-    manager = new RoundChangeManager(2, validators, messageValidators::get);
+    RoundChangeMessageValidator.MessageValidatorForHeightFactory messageValidatorFactory =
+        mock(RoundChangeMessageValidator.MessageValidatorForHeightFactory.class);
+
+    when(messageValidatorFactory.createAt(ri1))
+        .thenAnswer(
+            invocation ->
+                new MessageValidator(
+                    validators,
+                    Util.publicKeyToAddress(proposerKey.getPublicKey()),
+                    ri1,
+                    headerValidator,
+                    protocolContext,
+                    parentHeader));
+    when(messageValidatorFactory.createAt(ri2))
+        .thenAnswer(
+            invocation ->
+                new MessageValidator(
+                    validators,
+                    Util.publicKeyToAddress(validator1Key.getPublicKey()),
+                    ri2,
+                    headerValidator,
+                    protocolContext,
+                    parentHeader));
+    when(messageValidatorFactory.createAt(ri3))
+        .thenAnswer(
+            invocation ->
+                new MessageValidator(
+                    validators,
+                    Util.publicKeyToAddress(validator2Key.getPublicKey()),
+                    ri3,
+                    headerValidator,
+                    protocolContext,
+                    parentHeader));
+
+    manager = new RoundChangeManager(2, validators, messageValidatorFactory);
   }
 
   private SignedData<RoundChangePayload> makeRoundChangeMessage(