diff --git a/src/applications/diffusion/controller/DiffusionCloneController.php b/src/applications/diffusion/controller/DiffusionCloneController.php
index bf118bcf6d..7378383b25 100644
--- a/src/applications/diffusion/controller/DiffusionCloneController.php
+++ b/src/applications/diffusion/controller/DiffusionCloneController.php
@@ -23,24 +23,44 @@ final class DiffusionCloneController extends DiffusionController {
     $warning = null;
 
     $uris = $repository->getURIs();
-    foreach ($uris as $uri) {
-      if ($uri->getIsDisabled()) {
-        continue;
-      }
 
-      if ($uri->getEffectiveDisplayType() == $display_never) {
-        continue;
+    // If Differential is uninstalled and the repo is observed (=not hosted),
+    // only expose its external canonical URI, ignoring each URI's display
+    // preferences and ignoring if the canonical URI to observe is enabled.
+    if (!id(new PhabricatorDifferentialApplication())->isInstalled() &&
+        !$repository->isHosted()) {
+      foreach ($uris as $uri) {
+        if ($uri->getEffectiveIOType() == PhabricatorRepositoryURI::IO_OBSERVE) {
+          if ($repository->isSVN()) {
+            $label = phutil_tag_div('diffusion-clone-label', pht('Checkout'));
+          } else {
+            $label = phutil_tag_div('diffusion-clone-label', pht('Clone'));
+          }
+          $view->addProperty(
+            $label,
+            $this->renderCloneURI($repository, $uri));
+          break;
+        }
       }
-
-      if ($repository->isSVN()) {
-        $label = phutil_tag_div('diffusion-clone-label', pht('Checkout'));
-      } else {
-        $label = phutil_tag_div('diffusion-clone-label', pht('Clone'));
+    } else {
+      foreach ($uris as $uri) {
+        if ($uri->getIsDisabled()) {
+          continue;
+        }
+
+        if ($uri->getEffectiveDisplayType() == $display_never) {
+          continue;
+        }
+
+        if ($repository->isSVN()) {
+          $label = phutil_tag_div('diffusion-clone-label', pht('Checkout'));
+        } else {
+          $label = phutil_tag_div('diffusion-clone-label', pht('Clone'));
+        }
+
+        $view->addProperty(
+          $label,
+          $this->renderCloneURI($repository, $uri));
       }
-
-      $view->addProperty(
-        $label,
-        $this->renderCloneURI($repository, $uri));
     }
 
     if (!$view->hasAnyProperties()) {