diff --git a/pom.xml b/pom.xml
index af54b41..546d78f 100644
--- a/pom.xml
+++ b/pom.xml
@@ -4,7 +4,7 @@
 
     <groupId>com.gerritforge</groupId>
     <artifactId>global-refdb</artifactId>
-    <version>3.5.4.4</version>
+    <version>3.6.3.4</version>
     <packaging>jar</packaging>
 
     <name>global-refdb</name>
@@ -38,7 +38,7 @@
 
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <gerrit.version>3.5.4</gerrit.version>
+        <gerrit.version>3.6.3</gerrit.version>
     </properties>
 
     <dependencies>
@@ -81,7 +81,7 @@
                 <artifactId>maven-compiler-plugin</artifactId>
                 <version>3.6.1</version>
                 <configuration>
-                    <source>1.8</source>
+                    <source>11</source>
                     <target>11</target>
                 </configuration>
             </plugin>
diff --git a/src/main/java/com/gerritforge/gerrit/globalrefdb/validation/LibModuleLogFile.java b/src/main/java/com/gerritforge/gerrit/globalrefdb/validation/LibModuleLogFile.java
index c2858b4..7f10ef4 100644
--- a/src/main/java/com/gerritforge/gerrit/globalrefdb/validation/LibModuleLogFile.java
+++ b/src/main/java/com/gerritforge/gerrit/globalrefdb/validation/LibModuleLogFile.java
@@ -33,10 +33,11 @@
    * @see org.apache.log4j.PatternLayout
    */
   public LibModuleLogFile(SystemLog systemLog, String logName, Layout layout) {
-    AsyncAppender asyncAppender = systemLog.createAsyncAppender(logName, layout, true, true);
     Logger logger = LogManager.getLogger(logName);
-    logger.removeAppender(logName);
-    logger.addAppender(asyncAppender);
-    logger.setAdditivity(false);
+    if (logger.getAppender(logName) == null) {
+      AsyncAppender asyncAppender = systemLog.createAsyncAppender(logName, layout, true, true);
+      logger.addAppender(asyncAppender);
+      logger.setAdditivity(false);
+    }
   }
 }
diff --git a/src/main/java/com/gerritforge/gerrit/globalrefdb/validation/SharedRefDbGitRepositoryManager.java b/src/main/java/com/gerritforge/gerrit/globalrefdb/validation/SharedRefDbGitRepositoryManager.java
index 763aeb4..24bed90 100644
--- a/src/main/java/com/gerritforge/gerrit/globalrefdb/validation/SharedRefDbGitRepositoryManager.java
+++ b/src/main/java/com/gerritforge/gerrit/globalrefdb/validation/SharedRefDbGitRepositoryManager.java
@@ -25,7 +25,7 @@
 import com.google.inject.Singleton;
 import com.google.inject.name.Named;
 import java.io.IOException;
-import java.util.SortedSet;
+import java.util.NavigableSet;
 import org.eclipse.jgit.errors.RepositoryNotFoundException;
 import org.eclipse.jgit.lib.Repository;
 
@@ -110,7 +110,7 @@
   }
 
   @Override
-  public SortedSet<Project.NameKey> list() {
+  public NavigableSet<Project.NameKey> list() {
     return repositoryManager().list();
   }
 
diff --git a/src/test/java/com/gerritforge/gerrit/globalrefdb/validation/dfsrefdb/RefUpdateStub.java b/src/test/java/com/gerritforge/gerrit/globalrefdb/validation/dfsrefdb/RefUpdateStub.java
index e78ba6d..2da186b 100644
--- a/src/test/java/com/gerritforge/gerrit/globalrefdb/validation/dfsrefdb/RefUpdateStub.java
+++ b/src/test/java/com/gerritforge/gerrit/globalrefdb/validation/dfsrefdb/RefUpdateStub.java
@@ -15,7 +15,7 @@
 package com.gerritforge.gerrit.globalrefdb.validation.dfsrefdb;
 
 import java.io.IOException;
-import org.apache.commons.lang.NotImplementedException;
+import org.apache.commons.lang3.NotImplementedException;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.RefDatabase;