diff --git a/jvm-packages/xgboost4j-gpu/pom.xml b/jvm-packages/xgboost4j-gpu/pom.xml
index 4d35d2e76..1da88c3cc 100644
--- a/jvm-packages/xgboost4j-gpu/pom.xml
+++ b/jvm-packages/xgboost4j-gpu/pom.xml
@@ -41,13 +41,13 @@
         <dependency>
             <groupId>com.typesafe.akka</groupId>
             <artifactId>akka-actor_${scala.binary.version}</artifactId>
-            <version>2.7.0</version>
+            <version>2.6.20</version>
             <scope>compile</scope>
         </dependency>
         <dependency>
             <groupId>com.typesafe.akka</groupId>
             <artifactId>akka-testkit_${scala.binary.version}</artifactId>
-            <version>2.7.0</version>
+            <version>2.6.20</version>
             <scope>test</scope>
         </dependency>
         <dependency>
diff --git a/jvm-packages/xgboost4j-tester/generate_pom.py b/jvm-packages/xgboost4j-tester/generate_pom.py
index ff651a4f7..edc9759bd 100644
--- a/jvm-packages/xgboost4j-tester/generate_pom.py
+++ b/jvm-packages/xgboost4j-tester/generate_pom.py
@@ -51,13 +51,13 @@ pom_template = """
     <dependency>
       <groupId>com.typesafe.akka</groupId>
       <artifactId>akka-actor_${{scala.binary.version}}</artifactId>
-      <version>2.7.0</version>
+      <version>2.6.20</version>
       <scope>compile</scope>
     </dependency>
     <dependency>
       <groupId>com.typesafe.akka</groupId>
       <artifactId>akka-testkit_${{scala.binary.version}}</artifactId>
-      <version>2.7.0</version>
+      <version>2.6.20</version>
       <scope>test</scope>
     </dependency>
     <dependency>
diff --git a/jvm-packages/xgboost4j/pom.xml b/jvm-packages/xgboost4j/pom.xml
index dcc4bf60c..946b11108 100644
--- a/jvm-packages/xgboost4j/pom.xml
+++ b/jvm-packages/xgboost4j/pom.xml
@@ -34,13 +34,13 @@
         <dependency>
             <groupId>com.typesafe.akka</groupId>
             <artifactId>akka-actor_${scala.binary.version}</artifactId>
-            <version>2.7.0</version>
+            <version>2.6.20</version>
             <scope>compile</scope>
         </dependency>
         <dependency>
             <groupId>com.typesafe.akka</groupId>
             <artifactId>akka-testkit_${scala.binary.version}</artifactId>
-            <version>2.7.0</version>
+            <version>2.6.20</version>
             <scope>test</scope>
         </dependency>
         <dependency>