diff --git a/akka-cluster/src/main/java/akka/cluster/ClusterProtocol.java b/akka-cluster/src/main/java/akka/cluster/ClusterProtocol.java
index 840e89c015..54ca02a15f 100644
--- a/akka-cluster/src/main/java/akka/cluster/ClusterProtocol.java
+++ b/akka-cluster/src/main/java/akka/cluster/ClusterProtocol.java
@@ -402,7 +402,7 @@ public final class ClusterProtocol {
         maybeForceBuilderInitialization();
       }
       
-      private Builder(BuilderParent parent) {
+      private Builder(com.google.protobuf.GeneratedMessage.BuilderParent parent) {
         super(parent);
         maybeForceBuilderInitialization();
       }
@@ -1092,7 +1092,7 @@ public final class ClusterProtocol {
         maybeForceBuilderInitialization();
       }
       
-      private Builder(BuilderParent parent) {
+      private Builder(com.google.protobuf.GeneratedMessage.BuilderParent parent) {
         super(parent);
         maybeForceBuilderInitialization();
       }
@@ -1694,7 +1694,7 @@ public final class ClusterProtocol {
         maybeForceBuilderInitialization();
       }
       
-      private Builder(BuilderParent parent) {
+      private Builder(com.google.protobuf.GeneratedMessage.BuilderParent parent) {
         super(parent);
         maybeForceBuilderInitialization();
       }
diff --git a/akka-durable-mailboxes/akka-mailboxes-common/src/main/java/akka/actor/mailbox/MailboxProtocol.java b/akka-durable-mailboxes/akka-mailboxes-common/src/main/java/akka/actor/mailbox/MailboxProtocol.java
index bc128610cf..94c8cfde3e 100644
--- a/akka-durable-mailboxes/akka-mailboxes-common/src/main/java/akka/actor/mailbox/MailboxProtocol.java
+++ b/akka-durable-mailboxes/akka-mailboxes-common/src/main/java/akka/actor/mailbox/MailboxProtocol.java
@@ -323,7 +323,7 @@ public final class MailboxProtocol {
         maybeForceBuilderInitialization();
       }
       
-      private Builder(BuilderParent parent) {
+      private Builder(com.google.protobuf.GeneratedMessage.BuilderParent parent) {
         super(parent);
         maybeForceBuilderInitialization();
       }
@@ -925,7 +925,7 @@ public final class MailboxProtocol {
         maybeForceBuilderInitialization();
       }
       
-      private Builder(BuilderParent parent) {
+      private Builder(com.google.protobuf.GeneratedMessage.BuilderParent parent) {
         super(parent);
         maybeForceBuilderInitialization();
       }