diff --git a/src/applications/diffusion/controller/DiffusionRepositoryEditHostingController.php b/src/applications/diffusion/controller/DiffusionRepositoryEditHostingController.php
index 7b39aa3602..055ad5a958 100644
--- a/src/applications/diffusion/controller/DiffusionRepositoryEditHostingController.php
+++ b/src/applications/diffusion/controller/DiffusionRepositoryEditHostingController.php
@@ -126,6 +126,9 @@ final class DiffusionRepositoryEditHostingController
     $request = $this->getRequest();
     $user = $request->getUser();
 
+    $type = $repository->getVersionControlSystem();
+    $is_svn = ($type == PhabricatorRepositoryType::REPOSITORY_TYPE_SVN);
+
     $v_http_mode = $repository->getDetail(
       'serve-over-http',
       PhabricatorRepository::SERVE_OFF);
@@ -146,9 +149,11 @@ final class DiffusionRepositoryEditHostingController
       $type_http = PhabricatorRepositoryTransaction::TYPE_PROTOCOL_HTTP;
       $type_ssh = PhabricatorRepositoryTransaction::TYPE_PROTOCOL_SSH;
 
-      $xactions[] = id(clone $template)
-        ->setTransactionType($type_http)
-        ->setNewValue($v_http_mode);
+      if (!$is_svn) {
+        $xactions[] = id(clone $template)
+          ->setTransactionType($type_http)
+          ->setNewValue($v_http_mode);
+      }
 
       $xactions[] = id(clone $template)
         ->setTransactionType($type_ssh)
@@ -232,6 +237,18 @@ final class DiffusionRepositoryEditHostingController
             PhabricatorRepository::SERVE_READWRITE),
           $rw_message);
 
+    if ($is_svn) {
+      $http_control = id(new AphrontFormMarkupControl())
+        ->setLabel(pht('HTTP'))
+        ->setValue(
+          phutil_tag(
+            'em',
+            array(),
+            pht(
+              'Phabricator does not currently support HTTP access to '.
+              'Subversion repositories.')));
+    }
+
     $form = id(new AphrontFormView())
       ->setUser($user)
       ->appendRemarkupInstructions(
diff --git a/src/applications/diffusion/controller/DiffusionServeController.php b/src/applications/diffusion/controller/DiffusionServeController.php
index 6e78b89abc..3a7312c39a 100644
--- a/src/applications/diffusion/controller/DiffusionServeController.php
+++ b/src/applications/diffusion/controller/DiffusionServeController.php
@@ -172,18 +172,53 @@ final class DiffusionServeController extends DiffusionController {
           pht('This repository is not available over HTTP.'));
     }
 
-    switch ($repository->getVersionControlSystem()) {
-      case PhabricatorRepositoryType::REPOSITORY_TYPE_GIT:
-        $result = $this->serveGitRequest($repository, $viewer);
-        break;
-      case PhabricatorRepositoryType::REPOSITORY_TYPE_MERCURIAL:
-        $result = $this->serveMercurialRequest($repository, $viewer);
-        break;
-      default:
-        $result = new PhabricatorVCSResponse(
-          999,
-          pht('TODO: Implement meaningful responses.'));
-        break;
+    $vcs_type = $repository->getVersionControlSystem();
+    $req_type = $this->isVCSRequest($request);
+
+    if ($vcs_type != $req_type) {
+      switch ($req_type) {
+        case PhabricatorRepositoryType::REPOSITORY_TYPE_GIT:
+          $result = new PhabricatorVCSResponse(
+            500,
+            pht('This is not a Git repository.'));
+          break;
+        case PhabricatorRepositoryType::REPOSITORY_TYPE_MERCURIAL:
+          $result = new PhabricatorVCSResponse(
+            500,
+            pht('This is not a Mercurial repository.'));
+          break;
+        case PhabricatorRepositoryType::REPOSITORY_TYPE_SVN:
+          $result = new PhabricatorVCSResponse(
+            500,
+            pht('This is not a Subversion repository.'));
+          break;
+        default:
+          $result = new PhabricatorVCSResponse(
+            500,
+            pht('Unknown request type.'));
+          break;
+      }
+    } else {
+      switch ($vcs_type) {
+        case PhabricatorRepositoryType::REPOSITORY_TYPE_GIT:
+          $result = $this->serveGitRequest($repository, $viewer);
+          break;
+        case PhabricatorRepositoryType::REPOSITORY_TYPE_MERCURIAL:
+          $result = $this->serveMercurialRequest($repository, $viewer);
+          break;
+        case PhabricatorRepositoryType::REPOSITORY_TYPE_SVN:
+          $result = new PhabricatorVCSResponse(
+            500,
+            pht(
+              'Phabricator does not support HTTP access to Subversion '.
+              'repositories.'));
+          break;
+        default:
+          $result = new PhabricatorVCSResponse(
+            500,
+            pht('Unknown version control system.'));
+          break;
+      }
     }
 
     $code = $result->getHTTPResponseCode();
@@ -232,7 +267,7 @@ final class DiffusionServeController extends DiffusionController {
           return DiffusionMercurialWireProtocol::isReadOnlyBatchCommand($cmds);
         }
         return DiffusionMercurialWireProtocol::isReadOnlyCommand($cmd);
-      case PhabricatorRepositoryType::REPOSITORY_TYPE_SUBVERSION:
+      case PhabricatorRepositoryType::REPOSITORY_TYPE_SVN:
         break;
     }
 
diff --git a/src/applications/repository/storage/PhabricatorRepository.php b/src/applications/repository/storage/PhabricatorRepository.php
index 2174bdbadf..a4d140bba0 100644
--- a/src/applications/repository/storage/PhabricatorRepository.php
+++ b/src/applications/repository/storage/PhabricatorRepository.php
@@ -757,6 +757,9 @@ final class PhabricatorRepository extends PhabricatorRepositoryDAO
   }
 
   public function getServeOverHTTP() {
+    if ($this->isSVN()) {
+      return self::SERVE_OFF;
+    }
     $serve = $this->getDetail('serve-over-http', self::SERVE_OFF);
     return $this->normalizeServeConfigSetting($serve);
   }