diff --git a/pom.xml b/pom.xml
index beedafee1e..843f85d1a8 100644
--- a/pom.xml
+++ b/pom.xml
@@ -146,7 +146,7 @@
         <configuration>
           <signature>
             <groupId>org.codehaus.mojo.signature</groupId>
-            <artifactId>java16</artifactId>
+            <artifactId>java17</artifactId>
             <version>1.0</version>
           </signature>
         </configuration>
@@ -424,7 +424,7 @@
     <shiro.version>1.2.5</shiro.version>
 
     <!-- repostitory libraries -->
-    <jgit.version>3.7.1.201504261725-r-scm1</jgit.version>
+    <jgit.version>4.4.0.201606070830-r-scm1</jgit.version>
     <svnkit.version>1.8.5-scm2</svnkit.version>
 
     <!-- util libraries -->
@@ -432,7 +432,7 @@
     <quartz.version>2.2.3</quartz.version>
 
     <!-- build properties -->
-    <project.build.javaLevel>1.6</project.build.javaLevel>
+    <project.build.javaLevel>1.7</project.build.javaLevel>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <netbeans.hint.license>SCM-BSD</netbeans.hint.license>
     <jdk.classifier />
diff --git a/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/GitUtil.java b/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/GitUtil.java
index 8985966220..16a6f05541 100644
--- a/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/GitUtil.java
+++ b/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/GitUtil.java
@@ -264,7 +264,7 @@ public final class GitUtil
   {
     if (formatter != null)
     {
-      formatter.release();
+      formatter.close();
     }
   }
 
@@ -278,7 +278,7 @@ public final class GitUtil
   {
     if (walk != null)
     {
-      walk.release();
+      walk.close();
     }
   }
 
@@ -292,7 +292,7 @@ public final class GitUtil
   {
     if (walk != null)
     {
-      walk.release();
+      walk.close();;
     }
   }
 
diff --git a/scm-test/src/main/java/sonia/scm/repository/client/GitRepositoryClient.java b/scm-test/src/main/java/sonia/scm/repository/client/GitRepositoryClient.java
index 9f73fcb21a..9eba91d0e0 100644
--- a/scm-test/src/main/java/sonia/scm/repository/client/GitRepositoryClient.java
+++ b/scm-test/src/main/java/sonia/scm/repository/client/GitRepositoryClient.java
@@ -476,19 +476,10 @@ public class GitRepositoryClient extends AbstractRepositoryClient
   private RevCommit parseCommit(Ref branch)
     throws MissingObjectException, IncorrectObjectTypeException, IOException
   {
-    final RevWalk rw = new RevWalk(repository);
-    final RevCommit commit;
-
-    try
+    try (RevWalk rw = new RevWalk(repository))
     {
-      commit = rw.parseCommit(branch.getObjectId());
+      return rw.parseCommit(branch.getObjectId());
     }
-    finally
-    {
-      rw.release();
-    }
-
-    return commit;
   }
 
   /**