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 bddf9b378a..f5561c839a 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
@@ -16,12 +16,14 @@ import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.util.function.BiConsumer;
 import java.util.function.Consumer;
 
 /**
  * Use this {@link ModifyCommandBuilder} to make file changes to the head of a branch. You can
  * <ul>
- *   <li>create new files ({@link #createFile(String)}</li>
+ *   <li>create new files ({@link #createFile(String)} (with the option to overwrite a file, if it already exists; by
+ *   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>
@@ -66,24 +68,24 @@ public class ModifyCommandBuilder {
 
   /**
    * Create a new file. The content of the file will be specified in a subsequent call to
-   * {@link ContentLoader#withData(ByteSource)} or {@link ContentLoader#withData(InputStream)}.
+   * {@link SimpleContentLoader#withData(ByteSource)} or {@link SimpleContentLoader#withData(InputStream)}.
    * @param path The path and the name of the file that should be created.
    * @return The loader to specify the content of the new file.
    */
-  public ContentLoader createFile(String path) {
-    return new ContentLoader(
-      content -> request.addRequest(new ModifyCommandRequest.CreateFileRequest(path, content))
+  public WithOverwriteFlagContentLoader createFile(String path) {
+    return new WithOverwriteFlagContentLoader(
+      (content, overwrite) -> request.addRequest(new ModifyCommandRequest.CreateFileRequest(path, content, overwrite))
     );
   }
 
   /**
    * Modify an existing file. The new content of the file will be specified in a subsequent call to
-   * {@link ContentLoader#withData(ByteSource)} or {@link ContentLoader#withData(InputStream)}.
+   * {@link SimpleContentLoader#withData(ByteSource)} or {@link SimpleContentLoader#withData(InputStream)}.
    * @param path The path and the name of the file that should be modified.
    * @return The loader to specify the new content of the file.
    */
-  public ContentLoader modifyFile(String path) {
-    return new ContentLoader(
+  public SimpleContentLoader modifyFile(String path) {
+    return new SimpleContentLoader(
       content -> request.addRequest(new ModifyCommandRequest.ModifyFileRequest(path, content))
     );
   }
@@ -153,30 +155,39 @@ public class ModifyCommandBuilder {
     return this;
   }
 
-  public class ContentLoader {
-
-    private final Consumer<File> contentConsumer;
-
-    private ContentLoader(Consumer<File> contentConsumer) {
-      this.contentConsumer = contentConsumer;
-    }
-
+  public interface ContentLoader {
     /**
      * Specify the data of the file using a {@link ByteSource}.
+     *
      * @return The builder instance.
      * @throws IOException If the data could not be read.
      */
-    public ModifyCommandBuilder withData(ByteSource data) throws IOException {
-      File content = loadData(data);
-      contentConsumer.accept(content);
-      return ModifyCommandBuilder.this;
-    }
+    ModifyCommandBuilder withData(ByteSource data) throws IOException;
 
     /**
      * Specify the data of the file using an {@link InputStream}.
      * @return The builder instance.
      * @throws IOException If the data could not be read.
      */
+    ModifyCommandBuilder withData(InputStream data) throws IOException;
+  }
+
+  public class SimpleContentLoader implements ContentLoader {
+
+    private final Consumer<File> contentConsumer;
+
+    private SimpleContentLoader(Consumer<File> contentConsumer) {
+      this.contentConsumer = contentConsumer;
+    }
+
+    @Override
+    public ModifyCommandBuilder withData(ByteSource data) throws IOException {
+      File content = loadData(data);
+      contentConsumer.accept(content);
+      return ModifyCommandBuilder.this;
+    }
+
+    @Override
     public ModifyCommandBuilder withData(InputStream data) throws IOException {
       File content = loadData(data);
       contentConsumer.accept(content);
@@ -184,6 +195,36 @@ public class ModifyCommandBuilder {
     }
   }
 
+  public class WithOverwriteFlagContentLoader implements ContentLoader {
+
+    private final ContentLoader contentLoader;
+    private boolean overwrite = false;
+
+    private WithOverwriteFlagContentLoader(BiConsumer<File, Boolean> contentConsumer) {
+      this.contentLoader = new SimpleContentLoader(file -> contentConsumer.accept(file, overwrite));
+    }
+
+    /**
+     * Set this to <code>true</code> to overwrite the file if it already exists. Otherwise an
+     * {@link sonia.scm.AlreadyExistsException} will be thrown.
+     * @return This loader instance.
+     */
+    public WithOverwriteFlagContentLoader setOverwrite(boolean overwrite) {
+      this.overwrite = overwrite;
+      return this;
+    }
+
+    @Override
+    public ModifyCommandBuilder withData(ByteSource data) throws IOException {
+      return contentLoader.withData(data);
+    }
+
+    @Override
+    public ModifyCommandBuilder withData(InputStream data) throws IOException {
+      return contentLoader.withData(data);
+    }
+  }
+
   @SuppressWarnings("UnstableApiUsage") // Files only used internal
   private File loadData(ByteSource data) throws IOException {
     File file = createTemporaryFile();
diff --git a/scm-core/src/main/java/sonia/scm/repository/spi/ModifyCommand.java b/scm-core/src/main/java/sonia/scm/repository/spi/ModifyCommand.java
index a8b3efd6d9..578944c47f 100644
--- a/scm-core/src/main/java/sonia/scm/repository/spi/ModifyCommand.java
+++ b/scm-core/src/main/java/sonia/scm/repository/spi/ModifyCommand.java
@@ -10,7 +10,7 @@ public interface ModifyCommand {
   interface Worker {
     void delete(String toBeDeleted);
 
-    void create(String toBeCreated, File file) throws IOException;
+    void create(String toBeCreated, File file, boolean overwrite) throws IOException;
 
     void modify(String path, File file);
 
diff --git a/scm-core/src/main/java/sonia/scm/repository/spi/ModifyCommandRequest.java b/scm-core/src/main/java/sonia/scm/repository/spi/ModifyCommandRequest.java
index 94bf84ae70..723b287b6e 100644
--- a/scm-core/src/main/java/sonia/scm/repository/spi/ModifyCommandRequest.java
+++ b/scm-core/src/main/java/sonia/scm/repository/spi/ModifyCommandRequest.java
@@ -124,15 +124,17 @@ public class ModifyCommandRequest implements Resetable, Validateable {
   public static class CreateFileRequest extends ContentModificationRequest {
 
     private final String path;
+    private final boolean overwrite;
 
-    public CreateFileRequest(String path, File content) {
+    public CreateFileRequest(String path, File content, boolean overwrite) {
       super(content);
       this.path = path;
+      this.overwrite = overwrite;
     }
 
     @Override
     public void execute(ModifyCommand.Worker worker) throws IOException {
-      worker.create(path, getContent());
+      worker.create(path, getContent(), overwrite);
       cleanup();
     }
   }
diff --git a/scm-core/src/test/java/sonia/scm/repository/api/ModifyCommandBuilderTest.java b/scm-core/src/test/java/sonia/scm/repository/api/ModifyCommandBuilderTest.java
index d88d720cdb..db9a247d65 100644
--- a/scm-core/src/test/java/sonia/scm/repository/api/ModifyCommandBuilderTest.java
+++ b/scm-core/src/test/java/sonia/scm/repository/api/ModifyCommandBuilderTest.java
@@ -1,6 +1,7 @@
 package sonia.scm.repository.api;
 
 import com.google.common.io.ByteSource;
+import com.sun.org.apache.xpath.internal.operations.Bool;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
@@ -25,6 +26,7 @@ import java.util.List;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyBoolean;
 import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.doNothing;
 import static org.mockito.Mockito.lenient;
@@ -96,7 +98,7 @@ class ModifyCommandBuilderTest {
   void shouldExecuteCreateWithByteSourceContent() throws IOException {
     ArgumentCaptor<String> nameCaptor = ArgumentCaptor.forClass(String.class);
     List<String> contentCaptor = new ArrayList<>();
-    doAnswer(new ExtractContent(contentCaptor)).when(worker).create(nameCaptor.capture(), any());
+    doAnswer(new ExtractContent(contentCaptor)).when(worker).create(nameCaptor.capture(), any(), anyBoolean());
 
     initCommand()
       .createFile("toBeCreated").withData(ByteSource.wrap("content".getBytes()))
@@ -110,7 +112,7 @@ class ModifyCommandBuilderTest {
   void shouldExecuteCreateWithInputStreamContent() throws IOException {
     ArgumentCaptor<String> nameCaptor = ArgumentCaptor.forClass(String.class);
     List<String> contentCaptor = new ArrayList<>();
-    doAnswer(new ExtractContent(contentCaptor)).when(worker).create(nameCaptor.capture(), any());
+    doAnswer(new ExtractContent(contentCaptor)).when(worker).create(nameCaptor.capture(), any(), anyBoolean());
 
     initCommand()
       .createFile("toBeCreated").withData(new ByteArrayInputStream("content".getBytes()))
@@ -120,11 +122,43 @@ class ModifyCommandBuilderTest {
     assertThat(contentCaptor).contains("content");
   }
 
+  @Test
+  void shouldExecuteCreateWithOverwriteFalseAsDefault() throws IOException {
+    ArgumentCaptor<String> nameCaptor = ArgumentCaptor.forClass(String.class);
+    ArgumentCaptor<Boolean> overwriteCaptor = ArgumentCaptor.forClass(Boolean.class);
+    List<String> contentCaptor = new ArrayList<>();
+    doAnswer(new ExtractContent(contentCaptor)).when(worker).create(nameCaptor.capture(), any(), overwriteCaptor.capture());
+
+    initCommand()
+      .createFile("toBeCreated").withData(new ByteArrayInputStream("content".getBytes()))
+      .execute();
+
+    assertThat(nameCaptor.getValue()).isEqualTo("toBeCreated");
+    assertThat(overwriteCaptor.getValue()).isFalse();
+    assertThat(contentCaptor).contains("content");
+  }
+
+  @Test
+  void shouldExecuteCreateWithOverwriteIfSet() throws IOException {
+    ArgumentCaptor<String> nameCaptor = ArgumentCaptor.forClass(String.class);
+    ArgumentCaptor<Boolean> overwriteCaptor = ArgumentCaptor.forClass(Boolean.class);
+    List<String> contentCaptor = new ArrayList<>();
+    doAnswer(new ExtractContent(contentCaptor)).when(worker).create(nameCaptor.capture(), any(), overwriteCaptor.capture());
+
+    initCommand()
+      .createFile("toBeCreated").setOverwrite(true).withData(new ByteArrayInputStream("content".getBytes()))
+      .execute();
+
+    assertThat(nameCaptor.getValue()).isEqualTo("toBeCreated");
+    assertThat(overwriteCaptor.getValue()).isTrue();
+    assertThat(contentCaptor).contains("content");
+  }
+
   @Test
   void shouldExecuteCreateMultipleTimes() throws IOException {
     ArgumentCaptor<String> nameCaptor = ArgumentCaptor.forClass(String.class);
     List<String> contentCaptor = new ArrayList<>();
-    doAnswer(new ExtractContent(contentCaptor)).when(worker).create(nameCaptor.capture(), any());
+    doAnswer(new ExtractContent(contentCaptor)).when(worker).create(nameCaptor.capture(), any(), anyBoolean());
 
     initCommand()
       .createFile("toBeCreated_1").withData(new ByteArrayInputStream("content_1".getBytes()))
diff --git a/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/spi/GitModifyCommand.java b/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/spi/GitModifyCommand.java
index 8825645a3c..2c473398c5 100644
--- a/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/spi/GitModifyCommand.java
+++ b/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/spi/GitModifyCommand.java
@@ -8,9 +8,14 @@ import sonia.scm.repository.Repository;
 
 import java.io.File;
 import java.io.IOException;
+import java.nio.file.FileAlreadyExistsException;
 import java.nio.file.Files;
 import java.nio.file.Path;
 
+import static java.nio.file.StandardCopyOption.REPLACE_EXISTING;
+import static sonia.scm.AlreadyExistsException.alreadyExists;
+import static sonia.scm.ContextEntry.ContextBuilder.entity;
+
 public class GitModifyCommand extends AbstractGitCommand implements ModifyCommand {
 
   private final GitWorkdirFactory workdirFactory;
@@ -48,10 +53,18 @@ public class GitModifyCommand extends AbstractGitCommand implements ModifyComman
     }
 
     @Override
-    public void create(String toBeCreated, File file) throws IOException {
+    public void create(String toBeCreated, File file, boolean overwrite) throws IOException {
       Path targetFile = new File(workDir, toBeCreated).toPath();
       Files.createDirectories(targetFile.getParent());
-      Files.copy(file.toPath(), targetFile);
+      if (overwrite) {
+        Files.copy(file.toPath(), targetFile, REPLACE_EXISTING);
+      } else {
+        try {
+          Files.copy(file.toPath(), targetFile);
+        } catch (FileAlreadyExistsException e) {
+          throw alreadyExists(entity("file", toBeCreated).in("branch", request.getBranch()).in(context.getRepository()));
+        }
+      }
       try {
         getClone().add().addFilepattern(toBeCreated).call();
       } catch (GitAPIException e) {
diff --git a/scm-plugins/scm-git-plugin/src/test/java/sonia/scm/repository/spi/GitModifyCommandTest.java b/scm-plugins/scm-git-plugin/src/test/java/sonia/scm/repository/spi/GitModifyCommandTest.java
index e8574b7baf..2d9f5d0235 100644
--- a/scm-plugins/scm-git-plugin/src/test/java/sonia/scm/repository/spi/GitModifyCommandTest.java
+++ b/scm-plugins/scm-git-plugin/src/test/java/sonia/scm/repository/spi/GitModifyCommandTest.java
@@ -13,6 +13,7 @@ import org.eclipse.jgit.treewalk.CanonicalTreeParser;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
+import sonia.scm.AlreadyExistsException;
 import sonia.scm.repository.Person;
 import sonia.scm.repository.util.WorkdirProvider;
 
@@ -41,7 +42,7 @@ public class GitModifyCommandTest extends AbstractGitCommandTestBase {
     ModifyCommandRequest request = new ModifyCommandRequest();
     request.setBranch("master");
     request.setCommitMessage("test commit");
-    request.addRequest(new ModifyCommandRequest.CreateFileRequest("new_file", newFile));
+    request.addRequest(new ModifyCommandRequest.CreateFileRequest("new_file", newFile, false));
     request.setAuthor(new Person("Dirk Gently", "dirk@holistic.det"));
 
     String newRef = command.execute(request);
@@ -63,7 +64,7 @@ public class GitModifyCommandTest extends AbstractGitCommandTestBase {
     ModifyCommandRequest request = new ModifyCommandRequest();
     request.setBranch("master");
     request.setCommitMessage("test commit");
-    request.addRequest(new ModifyCommandRequest.CreateFileRequest("new_file", newFile));
+    request.addRequest(new ModifyCommandRequest.CreateFileRequest("new_file", newFile, false));
     request.setAuthor(new Person("Dirk Gently", "dirk@holistic.det"));
 
     command.execute(request);
@@ -73,6 +74,40 @@ public class GitModifyCommandTest extends AbstractGitCommandTestBase {
     assertInTree(assertions);
   }
 
+  @Test(expected = AlreadyExistsException.class)
+  public void shouldFailIfOverwritingExistingFileWithoutOverwriteFlag() throws IOException, GitAPIException {
+    File newFile = Files.write(temporaryFolder.newFile().toPath(), "new content".getBytes()).toFile();
+
+    GitModifyCommand command = createCommand();
+
+    ModifyCommandRequest request = new ModifyCommandRequest();
+    request.setBranch("master");
+    request.setCommitMessage("test commit");
+    request.addRequest(new ModifyCommandRequest.CreateFileRequest("a.txt", newFile, false));
+    request.setAuthor(new Person("Dirk Gently", "dirk@holistic.det"));
+
+    command.execute(request);
+  }
+
+  @Test
+  public void shouldOverwriteExistingFileIfOverwriteFlagSet() throws IOException, GitAPIException {
+    File newFile = Files.write(temporaryFolder.newFile().toPath(), "new content".getBytes()).toFile();
+
+    GitModifyCommand command = createCommand();
+
+    ModifyCommandRequest request = new ModifyCommandRequest();
+    request.setBranch("master");
+    request.setCommitMessage("test commit");
+    request.addRequest(new ModifyCommandRequest.CreateFileRequest("a.txt", newFile, true));
+    request.setAuthor(new Person("Dirk Gently", "dirk@holistic.det"));
+
+    command.execute(request);
+
+    TreeAssertions assertions = canonicalTreeParser -> assertThat(canonicalTreeParser.findFile("a.txt")).isTrue();
+
+    assertInTree(assertions);
+  }
+
   private void assertInTree(TreeAssertions assertions) throws IOException, GitAPIException {
     try (Git git = new Git(createContext().open())) {
       RevCommit lastCommit = getLastCommit(git);