diff --git a/gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/api/project/ProjectIT.java b/gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/api/project/ProjectIT.java
index d3187fc9a2..9b24922cbb 100644
--- a/gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/api/project/ProjectIT.java
+++ b/gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/api/project/ProjectIT.java
@@ -20,6 +20,7 @@ import com.google.gerrit.acceptance.AbstractDaemonTest;
 import com.google.gerrit.acceptance.NoHttpd;
 import com.google.gerrit.extensions.api.projects.BranchInput;
 import com.google.gerrit.extensions.api.projects.ProjectInput;
+import com.google.gerrit.extensions.restapi.ResourceConflictException;
 import com.google.gerrit.extensions.restapi.RestApiException;
 
 import org.eclipse.jgit.api.errors.GitAPIException;
@@ -50,6 +51,18 @@ public class ProjectIT extends AbstractDaemonTest  {
         .create(in);
   }
 
+  @Test(expected = ResourceConflictException.class)
+  public void createProjectDuplicate() throws RestApiException {
+    ProjectInput in = new ProjectInput();
+    in.name = "baz";
+    gApi.projects()
+        .name("baz")
+        .create(in);
+    gApi.projects()
+        .name("baz")
+        .create(in);
+  }
+
   @Test
   public void createBranch() throws GitAPIException,
       IOException, RestApiException {
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/api/projects/ProjectApiImpl.java b/gerrit-server/src/main/java/com/google/gerrit/server/api/projects/ProjectApiImpl.java
index 4086011824..b2a1244367 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/api/projects/ProjectApiImpl.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/api/projects/ProjectApiImpl.java
@@ -96,6 +96,9 @@ public class ProjectApiImpl implements ProjectApi {
   @Override
   public ProjectApi create(ProjectInput in) throws RestApiException {
     try {
+      if (name == null) {
+        throw new ResourceConflictException("Project already exists");
+      }
       if (in.name != null && !name.equals(in.name)) {
         throw new RestApiException("name must match input.name");
       }
@@ -103,8 +106,8 @@ public class ProjectApiImpl implements ProjectApi {
           .apply(TopLevelResource.INSTANCE, in);
       return projectApi.create(projects.parse(name));
     } catch (BadRequestException | UnprocessableEntityException
-        | ResourceConflictException | ResourceNotFoundException
-        | ProjectCreationFailedException | IOException e) {
+        | ResourceNotFoundException | ProjectCreationFailedException
+        | IOException e) {
       throw new RestApiException("Cannot create project", e);
     }
   }