diff --git a/scm-core/src/main/java/sonia/scm/repository/api/MergeCommandBuilder.java b/scm-core/src/main/java/sonia/scm/repository/api/MergeCommandBuilder.java
index a751832d8f..6cbf2caa8c 100644
--- a/scm-core/src/main/java/sonia/scm/repository/api/MergeCommandBuilder.java
+++ b/scm-core/src/main/java/sonia/scm/repository/api/MergeCommandBuilder.java
@@ -32,6 +32,7 @@ import sonia.scm.repository.spi.MergeConflictResult;
 import sonia.scm.repository.util.AuthorUtil;
 import sonia.scm.user.EMail;
 
+import javax.annotation.Nullable;
 import java.util.Set;
 
 /**
@@ -76,12 +77,13 @@ import java.util.Set;
  */
 public class MergeCommandBuilder {
 
-  private final EMail eMail;
-
   private final MergeCommand mergeCommand;
   private final MergeCommandRequest request = new MergeCommandRequest();
 
-  MergeCommandBuilder(MergeCommand mergeCommand, EMail eMail) {
+  @Nullable
+  private final EMail eMail;
+
+  MergeCommandBuilder(MergeCommand mergeCommand, @Nullable EMail eMail) {
     this.mergeCommand = mergeCommand;
     this.eMail = eMail;
   }
diff --git a/scm-core/src/main/java/sonia/scm/repository/api/ModifyCommandBuilder.java b/scm-core/src/main/java/sonia/scm/repository/api/ModifyCommandBuilder.java
index 795de5d43d..f2b11a00a0 100644
--- a/scm-core/src/main/java/sonia/scm/repository/api/ModifyCommandBuilder.java
+++ b/scm-core/src/main/java/sonia/scm/repository/api/ModifyCommandBuilder.java
@@ -38,6 +38,7 @@ import sonia.scm.repository.work.WorkdirProvider;
 import sonia.scm.user.EMail;
 import sonia.scm.util.IOUtil;
 
+import javax.annotation.Nullable;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
@@ -52,7 +53,6 @@ import java.util.function.Consumer;
  *   default a {@link sonia.scm.AlreadyExistsException} will be thrown)</li>
  *   <li>modify existing files ({@link #modifyFile(String)}</li>
  *   <li>delete existing files ({@link #deleteFile(String)}</li>
- *   <li>move/rename existing files ({@link #moveFile(String, String)}</li>
  * </ul>
  *
  * You can collect multiple changes before they are executed with a call to {@link #execute()}.
@@ -73,14 +73,15 @@ public class ModifyCommandBuilder {
 
   private static final Logger LOG = LoggerFactory.getLogger(ModifyCommandBuilder.class);
 
-  private final EMail eMail;
-
   private final ModifyCommand command;
   private final File workdir;
 
+  @Nullable
+  private final EMail eMail;
+
   private final ModifyCommandRequest request = new ModifyCommandRequest();
 
-  ModifyCommandBuilder(ModifyCommand command, WorkdirProvider workdirProvider, EMail eMail) {
+  ModifyCommandBuilder(ModifyCommand command, WorkdirProvider workdirProvider, @Nullable EMail eMail) {
     this.command = command;
     this.workdir = workdirProvider.createNewWorkdir();
     this.eMail = eMail;
diff --git a/scm-core/src/main/java/sonia/scm/repository/api/RepositoryService.java b/scm-core/src/main/java/sonia/scm/repository/api/RepositoryService.java
index 029dc6fa34..aa2a41782d 100644
--- a/scm-core/src/main/java/sonia/scm/repository/api/RepositoryService.java
+++ b/scm-core/src/main/java/sonia/scm/repository/api/RepositoryService.java
@@ -36,6 +36,7 @@ import sonia.scm.repository.spi.RepositoryServiceProvider;
 import sonia.scm.repository.work.WorkdirProvider;
 import sonia.scm.user.EMail;
 
+import javax.annotation.Nullable;
 import java.io.Closeable;
 import java.io.IOException;
 import java.util.Set;
@@ -85,9 +86,11 @@ public final class RepositoryService implements Closeable {
   private final PreProcessorUtil preProcessorUtil;
   private final RepositoryServiceProvider provider;
   private final Repository repository;
-  @SuppressWarnings("rawtypes")
+  @SuppressWarnings({"rawtypes", "java:S3740"})
   private final Set<ScmProtocolProvider> protocolProviders;
   private final WorkdirProvider workdirProvider;
+
+  @Nullable
   private final EMail eMail;
 
   /**
@@ -100,11 +103,12 @@ public final class RepositoryService implements Closeable {
    * @param eMail            utility to compute email addresses if missing
    */
   RepositoryService(CacheManager cacheManager,
-                    RepositoryServiceProvider provider, Repository repository,
+                    RepositoryServiceProvider provider,
+                    Repository repository,
                     PreProcessorUtil preProcessorUtil,
-                    @SuppressWarnings("rawtypes") Set<ScmProtocolProvider> protocolProviders,
+                    @SuppressWarnings({"rawtypes", "java:S3740"}) Set<ScmProtocolProvider> protocolProviders,
                     WorkdirProvider workdirProvider,
-                    EMail eMail) {
+                    @Nullable EMail eMail) {
     this.cacheManager = cacheManager;
     this.provider = provider;
     this.repository = repository;
@@ -452,7 +456,7 @@ public final class RepositoryService implements Closeable {
       .map(this::createProviderInstanceForRepository);
   }
 
-  @SuppressWarnings("rawtypes")
+  @SuppressWarnings({"rawtypes", "java:S3740"})
   private ScmProtocol createProviderInstanceForRepository(ScmProtocolProvider protocolProvider) {
     return protocolProvider.get(repository);
   }
diff --git a/scm-core/src/main/java/sonia/scm/repository/util/AuthorUtil.java b/scm-core/src/main/java/sonia/scm/repository/util/AuthorUtil.java
index 1df0e5ef76..21142ba95d 100644
--- a/scm-core/src/main/java/sonia/scm/repository/util/AuthorUtil.java
+++ b/scm-core/src/main/java/sonia/scm/repository/util/AuthorUtil.java
@@ -30,19 +30,21 @@ import sonia.scm.repository.Person;
 import sonia.scm.user.EMail;
 import sonia.scm.user.User;
 
+import javax.annotation.Nullable;
+
 public class AuthorUtil {
 
   public static void setAuthorIfNotAvailable(CommandWithAuthor request) {
     setAuthorIfNotAvailable(request, null);
   }
 
-  public static void setAuthorIfNotAvailable(CommandWithAuthor request, EMail eMail) {
+  public static void setAuthorIfNotAvailable(CommandWithAuthor request, @Nullable EMail eMail) {
     if (request.getAuthor() == null) {
       request.setAuthor(createAuthorFromSubject(eMail));
     }
   }
 
-  private static Person createAuthorFromSubject(EMail eMail) {
+  private static Person createAuthorFromSubject(@Nullable EMail eMail) {
     Subject subject = SecurityUtils.getSubject();
     User user = subject.getPrincipals().oneByType(User.class);
     String name = user.getDisplayName();