diff --git a/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/api/v2/resources/GitRepositoryConfigToGitRepositoryConfigDtoMapper.java b/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/api/v2/resources/GitRepositoryConfigMapper.java
similarity index 86%
rename from scm-plugins/scm-git-plugin/src/main/java/sonia/scm/api/v2/resources/GitRepositoryConfigToGitRepositoryConfigDtoMapper.java
rename to scm-plugins/scm-git-plugin/src/main/java/sonia/scm/api/v2/resources/GitRepositoryConfigMapper.java
index 07fd83b700..6480e526b1 100644
--- a/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/api/v2/resources/GitRepositoryConfigToGitRepositoryConfigDtoMapper.java
+++ b/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/api/v2/resources/GitRepositoryConfigMapper.java
@@ -17,15 +17,16 @@ import static de.otto.edison.hal.Links.linkingTo;
 // Mapstruct does not support parameterized (i.e. non-default) constructors. Thus, we need to use field injection.
 @SuppressWarnings("squid:S3306")
 @Mapper
-public abstract class GitRepositoryConfigToGitRepositoryConfigDtoMapper {
+public abstract class GitRepositoryConfigMapper {
 
   @Inject
   private ScmPathInfoStore scmPathInfoStore;
 
   public abstract GitRepositoryConfigDto map(GitRepositoryConfig config, @Context Repository repository);
+  public abstract GitRepositoryConfig map(GitRepositoryConfigDto dto);
 
   @AfterMapping
-  void appendLinks(GitRepositoryConfig config, @MappingTarget GitRepositoryConfigDto target, @Context Repository repository) {
+  void appendLinks(@MappingTarget GitRepositoryConfigDto target, @Context Repository repository) {
     Links.Builder linksBuilder = linkingTo().self(self());
     if (RepositoryPermissions.modify(repository).isPermitted()) {
       linksBuilder.single(link("update", update()));
diff --git a/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/api/v2/resources/GitRepositoryConfigResource.java b/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/api/v2/resources/GitRepositoryConfigResource.java
index 2ff637031b..af3501ae9a 100644
--- a/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/api/v2/resources/GitRepositoryConfigResource.java
+++ b/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/api/v2/resources/GitRepositoryConfigResource.java
@@ -9,7 +9,9 @@ import sonia.scm.store.ConfigurationStoreFactory;
 import sonia.scm.web.GitVndMediaType;
 
 import javax.inject.Inject;
+import javax.ws.rs.Consumes;
 import javax.ws.rs.GET;
+import javax.ws.rs.PUT;
 import javax.ws.rs.Path;
 import javax.ws.rs.PathParam;
 import javax.ws.rs.Produces;
@@ -20,13 +22,13 @@ import static sonia.scm.NotFoundException.notFound;
 
 public class GitRepositoryConfigResource {
 
-  private final GitRepositoryConfigToGitRepositoryConfigDtoMapper repositoryConfigToDtoMapper;
+  private final GitRepositoryConfigMapper repositoryConfigMapper;
   private final RepositoryManager repositoryManager;
   private final ConfigurationStoreFactory configurationStoreFactory;
 
   @Inject
-  public GitRepositoryConfigResource(GitRepositoryConfigToGitRepositoryConfigDtoMapper repositoryConfigToDtoMapper, RepositoryManager repositoryManager, ConfigurationStoreFactory configurationStoreFactory) {
-    this.repositoryConfigToDtoMapper = repositoryConfigToDtoMapper;
+  public GitRepositoryConfigResource(GitRepositoryConfigMapper repositoryConfigMapper, RepositoryManager repositoryManager, ConfigurationStoreFactory configurationStoreFactory) {
+    this.repositoryConfigMapper = repositoryConfigMapper;
     this.repositoryManager = repositoryManager;
     this.configurationStoreFactory = configurationStoreFactory;
   }
@@ -35,18 +37,37 @@ public class GitRepositoryConfigResource {
   @Path("/")
   @Produces(GitVndMediaType.GIT_REPOSITORY_CONFIG)
   public Response getRepositoryConfig(@PathParam("namespace") String namespace, @PathParam("name") String name) {
+    Repository repository = getRepository(namespace, name);
+    ConfigurationStore<GitRepositoryConfig> repositoryConfigStore = getStore(repository);
+    GitRepositoryConfig config = repositoryConfigStore.get();
+    if (config == null) {
+      config = new GitRepositoryConfig();
+    }
+    GitRepositoryConfigDto dto = repositoryConfigMapper.map(config, repository);
+    return Response.ok(dto).build();
+  }
+
+  @PUT
+  @Path("/")
+  @Consumes(GitVndMediaType.GIT_REPOSITORY_CONFIG)
+  public Response setRepositoryConfig(@PathParam("namespace") String namespace, @PathParam("name") String name, GitRepositoryConfigDto dto) {
+    Repository repository = getRepository(namespace, name);
+    ConfigurationStore<GitRepositoryConfig> repositoryConfigStore = getStore(repository);
+    GitRepositoryConfig config = repositoryConfigMapper.map(dto);
+    repositoryConfigStore.set(config);
+    return Response.noContent().build();
+  }
+
+  private Repository getRepository(@PathParam("namespace") String namespace, @PathParam("name") String name) {
     NamespaceAndName namespaceAndName = new NamespaceAndName(namespace, name);
     Repository repository = repositoryManager.get(namespaceAndName);
     if (repository == null) {
       throw notFound(entity(namespaceAndName));
     }
+    return repository;
+  }
 
-    ConfigurationStore<GitRepositoryConfig> repositoryConfigStore = configurationStoreFactory.withType(GitRepositoryConfig.class).withName("gitConfig").forRepository(repository).build();
-    GitRepositoryConfig config = repositoryConfigStore.get();
-    if (config == null) {
-      config = new GitRepositoryConfig();
-    }
-    GitRepositoryConfigDto dto = repositoryConfigToDtoMapper.map(config, repository);
-    return Response.ok(dto).build();
+  private ConfigurationStore<GitRepositoryConfig> getStore(Repository repository) {
+    return configurationStoreFactory.withType(GitRepositoryConfig.class).withName("gitConfig").forRepository(repository).build();
   }
 }
diff --git a/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/GitRepositoryConfig.java b/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/GitRepositoryConfig.java
index ae41987247..a548d82153 100644
--- a/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/GitRepositoryConfig.java
+++ b/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/GitRepositoryConfig.java
@@ -1,5 +1,11 @@
 package sonia.scm.repository;
 
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+import javax.xml.bind.annotation.XmlRootElement;
+
+@XmlRootElement(name = "config")
+@XmlAccessorType(XmlAccessType.FIELD)
 public class GitRepositoryConfig {
 
   private String defaultBranch;
diff --git a/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/web/GitServletModule.java b/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/web/GitServletModule.java
index 609ee6cb0b..0bbb993cc6 100644
--- a/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/web/GitServletModule.java
+++ b/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/web/GitServletModule.java
@@ -40,7 +40,7 @@ import org.eclipse.jgit.transport.ScmTransportProtocol;
 import org.mapstruct.factory.Mappers;
 import sonia.scm.api.v2.resources.GitConfigDtoToGitConfigMapper;
 import sonia.scm.api.v2.resources.GitConfigToGitConfigDtoMapper;
-import sonia.scm.api.v2.resources.GitRepositoryConfigToGitRepositoryConfigDtoMapper;
+import sonia.scm.api.v2.resources.GitRepositoryConfigMapper;
 import sonia.scm.plugin.Extension;
 import sonia.scm.repository.GitWorkdirFactory;
 import sonia.scm.repository.spi.SimpleGitWorkdirFactory;
@@ -66,7 +66,7 @@ public class GitServletModule extends ServletModule
 
     bind(GitConfigDtoToGitConfigMapper.class).to(Mappers.getMapper(GitConfigDtoToGitConfigMapper.class).getClass());
     bind(GitConfigToGitConfigDtoMapper.class).to(Mappers.getMapper(GitConfigToGitConfigDtoMapper.class).getClass());
-    bind(GitRepositoryConfigToGitRepositoryConfigDtoMapper.class).to(Mappers.getMapper(GitRepositoryConfigToGitRepositoryConfigDtoMapper.class).getClass());
+    bind(GitRepositoryConfigMapper.class).to(Mappers.getMapper(GitRepositoryConfigMapper.class).getClass());
 
     bind(GitWorkdirFactory.class).to(SimpleGitWorkdirFactory.class);
   }
diff --git a/scm-plugins/scm-git-plugin/src/test/java/sonia/scm/api/v2/resources/GitConfigResourceTest.java b/scm-plugins/scm-git-plugin/src/test/java/sonia/scm/api/v2/resources/GitConfigResourceTest.java
index 7bc0e5fe02..f4de22b2b5 100644
--- a/scm-plugins/scm-git-plugin/src/test/java/sonia/scm/api/v2/resources/GitConfigResourceTest.java
+++ b/scm-plugins/scm-git-plugin/src/test/java/sonia/scm/api/v2/resources/GitConfigResourceTest.java
@@ -12,8 +12,11 @@ import org.junit.Test;
 import org.junit.rules.ExpectedException;
 import org.junit.runner.RunWith;
 import org.mockito.Answers;
+import org.mockito.ArgumentCaptor;
+import org.mockito.Captor;
 import org.mockito.InjectMocks;
 import org.mockito.Mock;
+import org.mockito.Spy;
 import org.mockito.runners.MockitoJUnitRunner;
 import sonia.scm.repository.GitConfig;
 import sonia.scm.repository.GitRepositoryConfig;
@@ -35,6 +38,7 @@ import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.doNothing;
 import static org.mockito.Mockito.when;
 
 @SubjectAware(
@@ -66,21 +70,23 @@ public class GitConfigResourceTest {
   @InjectMocks
   private GitConfigToGitConfigDtoMapperImpl configToDtoMapper;
   @InjectMocks
-  private GitRepositoryConfigToGitRepositoryConfigDtoMapperImpl repositoryConfigToDtoMapper;
+  private GitRepositoryConfigMapperImpl repositoryConfigMapper;
 
   @Mock
   private GitRepositoryHandler repositoryHandler;
 
   @Mock(answer = Answers.CALLS_REAL_METHODS)
   private ConfigurationStoreFactory configurationStoreFactory;
-  @Mock
-  private ConfigurationStore configurationStore;
+  @Spy
+  private ConfigurationStore<Object> configurationStore;
+  @Captor
+  private ArgumentCaptor<Object> configurationStoreCaptor;
 
   @Before
   public void prepareEnvironment() {
     GitConfig gitConfig = createConfiguration();
     when(repositoryHandler.getConfig()).thenReturn(gitConfig);
-    GitRepositoryConfigResource gitRepositoryConfigResource = new GitRepositoryConfigResource(repositoryConfigToDtoMapper, repositoryManager, configurationStoreFactory);
+    GitRepositoryConfigResource gitRepositoryConfigResource = new GitRepositoryConfigResource(repositoryConfigMapper, repositoryManager, configurationStoreFactory);
     GitConfigResource gitConfigResource = new GitConfigResource(dtoToConfigMapper, configToDtoMapper, repositoryHandler, of(gitRepositoryConfigResource));
     dispatcher.getRegistry().addSingletonResource(gitConfigResource);
     when(scmPathInfoStore.get().getApiRestUri()).thenReturn(baseUri);
@@ -89,6 +95,7 @@ public class GitConfigResourceTest {
   @Before
   public void initConfigStore() {
     when(configurationStoreFactory.getStore(any())).thenReturn(configurationStore);
+    doNothing().when(configurationStore).set(configurationStoreCaptor.capture());
   }
 
   @Test
@@ -202,6 +209,26 @@ public class GitConfigResourceTest {
       .contains("\"defaultBranch\":\"test\"");
   }
 
+  @Test
+  @SubjectAware(username = "writeOnly")
+  public void shouldStoreChangedRepositoryConfig() throws URISyntaxException {
+    when(repositoryManager.get(new NamespaceAndName("space", "X"))).thenReturn(new Repository("id", "git", "space", "X"));
+
+    MockHttpRequest request = MockHttpRequest
+      .put("/" + GitConfigResource.GIT_CONFIG_PATH_V2 + "/space/X")
+      .contentType(GitVndMediaType.GIT_REPOSITORY_CONFIG)
+      .content("{\"defaultBranch\": \"new\"}".getBytes());
+    MockHttpResponse response = new MockHttpResponse();
+
+    dispatcher.invoke(request, response);
+
+    assertEquals(HttpServletResponse.SC_NO_CONTENT, response.getStatus());
+    assertThat(configurationStoreCaptor.getValue())
+      .isInstanceOfSatisfying(GitRepositoryConfig.class, x -> { })
+      .extracting("defaultBranch")
+      .containsExactly("new");
+  }
+
   private MockHttpResponse get() throws URISyntaxException {
     MockHttpRequest request = MockHttpRequest.get("/" + GitConfigResource.GIT_CONFIG_PATH_V2);
     MockHttpResponse response = new MockHttpResponse();