diff --git a/src/main/java/com/googlesource/gerrit/plugins/simplesubmitrules/config/ConfigServlet.java b/src/main/java/com/googlesource/gerrit/plugins/simplesubmitrules/config/ConfigServlet.java
index 87c7b08..9721b1e 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/simplesubmitrules/config/ConfigServlet.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/simplesubmitrules/config/ConfigServlet.java
@@ -18,17 +18,20 @@
 import com.google.gerrit.extensions.restapi.BadRequestException;
 import com.google.gerrit.extensions.restapi.RestModifyView;
 import com.google.gerrit.extensions.restapi.RestReadView;
+import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.git.meta.MetaDataUpdate;
 import com.google.gerrit.server.permissions.PermissionBackend;
 import com.google.gerrit.server.permissions.PermissionBackendException;
 import com.google.gerrit.server.permissions.ProjectPermission;
 import com.google.gerrit.server.project.ProjectCache;
+import com.google.gerrit.server.project.ProjectConfig;
 import com.google.gerrit.server.project.ProjectResource;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
 import com.googlesource.gerrit.plugins.simplesubmitrules.api.SubmitConfig;
 import java.io.IOException;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 
 /** REST Endpoint to configure labels and our simple submit rules */
 @Singleton
@@ -63,20 +66,22 @@
 
   @Override
   public Object apply(ProjectResource resource, SubmitConfig inConfig)
-      throws PermissionBackendException, AuthException, BadRequestException, IOException {
-
+      throws PermissionBackendException, AuthException, BadRequestException, ConfigInvalidException,
+          IOException {
+    Project.NameKey projectName = resource.getNameKey();
     permissionBackend
         .user(resource.getUser())
         .project(resource.getNameKey())
         .check(ProjectPermission.WRITE_CONFIG);
 
     IdentifiedUser user = resource.getUser().asIdentifiedUser();
-    try (MetaDataUpdate md = metaDataUpdateFactory.create(resource.getNameKey(), user)) {
-      configTranslator.applyTo(inConfig, resource.getProjectState());
-      resource.getProjectState().getConfig().commit(md);
-      projectCache.evict(resource.getNameKey());
+    try (MetaDataUpdate md = metaDataUpdateFactory.create(projectName, user)) {
+      ProjectConfig projectConfig = ProjectConfig.read(md);
+      configTranslator.applyTo(inConfig, projectConfig);
+      projectConfig.commit(md);
+      projectCache.evict(projectName);
     }
 
-    return configTranslator.convertFrom(projectCache.get(resource.getNameKey()));
+    return configTranslator.convertFrom(projectCache.checkedGet(projectName));
   }
 }
diff --git a/src/main/java/com/googlesource/gerrit/plugins/simplesubmitrules/config/ConfigTranslator.java b/src/main/java/com/googlesource/gerrit/plugins/simplesubmitrules/config/ConfigTranslator.java
index f7ff9b0..d9dea99 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/simplesubmitrules/config/ConfigTranslator.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/simplesubmitrules/config/ConfigTranslator.java
@@ -24,6 +24,7 @@
 import com.google.gerrit.extensions.restapi.BadRequestException;
 import com.google.gerrit.server.config.PluginConfig;
 import com.google.gerrit.server.config.PluginConfigFactory;
+import com.google.gerrit.server.project.ProjectCache;
 import com.google.gerrit.server.project.ProjectConfig;
 import com.google.gerrit.server.project.ProjectState;
 import com.google.inject.Inject;
@@ -32,6 +33,7 @@
 import com.googlesource.gerrit.plugins.simplesubmitrules.api.CommentsRules;
 import com.googlesource.gerrit.plugins.simplesubmitrules.api.LabelDefinition;
 import com.googlesource.gerrit.plugins.simplesubmitrules.api.SubmitConfig;
+import java.io.IOException;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
@@ -39,11 +41,16 @@
 /** Codec class used to convert {@link SubmitConfig} from/to a Gerrit config */
 @Singleton
 public final class ConfigTranslator {
+  private final ProjectCache projectCache;
   private final PluginConfigFactory pluginConfigFactory;
   private final String pluginName;
 
   @Inject
-  public ConfigTranslator(PluginConfigFactory pluginConfigFactory, @PluginName String pluginName) {
+  public ConfigTranslator(
+      ProjectCache projectCache,
+      PluginConfigFactory pluginConfigFactory,
+      @PluginName String pluginName) {
+    this.projectCache = projectCache;
     this.pluginConfigFactory = pluginConfigFactory;
     this.pluginName = pluginName;
   }
@@ -114,26 +121,30 @@
     return submitConfig;
   }
 
-  void applyTo(SubmitConfig inConfig, ProjectState projectState) throws BadRequestException {
+  void applyTo(SubmitConfig inConfig, ProjectConfig projectConfig)
+      throws BadRequestException, IOException {
     PluginConfig hostPluginConfig = pluginConfigFactory.getFromGerritConfig(pluginName);
-    PluginConfig projectPluginConfig =
-        pluginConfigFactory.getFromProjectConfig(projectState, pluginName);
+    PluginConfig projectPluginConfig = projectConfig.getPluginConfig(pluginName);
+
     applyCommentRulesTo(inConfig.comments, projectPluginConfig);
-    applyLabelsTo(inConfig.labels, projectState, hostPluginConfig);
+    applyLabelsTo(inConfig.labels, projectConfig, hostPluginConfig);
   }
 
-  private static void applyLabelsTo(
-      Map<String, LabelDefinition> labels, ProjectState projectState, PluginConfig hostPluginConfig)
-      throws BadRequestException {
+  private void applyLabelsTo(
+      Map<String, LabelDefinition> labels,
+      ProjectConfig projectConfig,
+      PluginConfig hostPluginConfig)
+      throws BadRequestException, IOException {
     if (labels.isEmpty()) {
       return;
     }
 
     for (Map.Entry<String, LabelDefinition> entry : labels.entrySet()) {
-      if (!projectState.getConfig().getLabelSections().containsKey(entry.getKey())) {
+      if (!projectConfig.getLabelSections().containsKey(entry.getKey())) {
         // The current project does not have this label. Try to copy it down from the inherited
         // labels to be able to modify it locally.
-        Map<String, LabelType> copiedLabelTypes = projectState.getConfig().getLabelSections();
+        Map<String, LabelType> copiedLabelTypes = projectConfig.getLabelSections();
+        ProjectState projectState = projectCache.checkedGet(projectConfig.getName());
         projectState
             .getLabelTypes()
             .getLabelTypes()
@@ -145,7 +156,7 @@
 
       String label = entry.getKey();
       LabelDefinition definition = entry.getValue();
-      LabelType labelType = projectState.getConfig().getLabelSections().get(label);
+      LabelType labelType = projectConfig.getLabelSections().get(label);
 
       if (labelType == null) {
         throw new BadRequestException(