diff --git a/src/Entity/Redirect.php b/src/Entity/Redirect.php
index c1796c1..e6ad36c 100644
--- a/src/Entity/Redirect.php
+++ b/src/Entity/Redirect.php
@@ -8,6 +8,7 @@ use Drupal\Core\Entity\ContentEntityBase;
 use Drupal\Core\Entity\EntityStorageInterface;
 use Drupal\Core\Entity\EntityTypeInterface;
 use Drupal\Core\Field\BaseFieldDefinition;
+use Drupal\Core\Language\LanguageInterface;
 use Drupal\link\LinkItemInterface;
 
 /**
@@ -85,9 +86,17 @@ class Redirect extends ContentEntityBase {
    * {@inheritdoc}
    */
   public function preSave(EntityStorageInterface $storage_controller) {
-    // Get the language code directly from the field as language() might not
-    // be up to date if the language was just changed.
-    $this->set('hash', Redirect::generateHash($this->redirect_source->path, (array) $this->redirect_source->query, $this->get('language')->value));
+    $path = $this->redirect_source->path;
+
+    // Get the language code directly from the field as language() might not be
+    // up to date if the language was just changed.
+    $redirect_language = $this->get('language')->value;
+
+    // Pass the path through the alias manager to convert it to the the alias's
+    // source. If it is not an alias the original value will be returned.
+    $path = ltrim(\Drupal::service('path.alias_manager')->getPathByAlias('/' . $path, $redirect_language), '/');
+
+    $this->set('hash', Redirect::generateHash($path, (array) $this->redirect_source->query, $redirect_language));
   }
 
   /**
diff --git a/src/EventSubscriber/RedirectRequestSubscriber.php b/src/EventSubscriber/RedirectRequestSubscriber.php
index cca4ac0..e83f9ea 100644
--- a/src/EventSubscriber/RedirectRequestSubscriber.php
+++ b/src/EventSubscriber/RedirectRequestSubscriber.php
@@ -162,6 +162,17 @@ class RedirectRequestSubscriber implements EventSubscriberInterface {
       if ($this->config->get('passthrough_querystring')) {
         $url->setOption('query', (array) $url->getOption('query') + $request_query);
       }
+
+      // Redirects to path aliases are stored and searched for using the alias's
+      // source (/node/123 vs /foo-bar-path). This can cause redirect loops
+      // because the path processor above may have converted a path alias to a
+      // path source (/foo-bar-path => /node/123) which will trigger a redirect
+      // on the path's valid alias.
+      $redirect_url = $url->setAbsolute()->toString();
+      if ($redirect_url === ($request->getSchemeAndHttpHost() . $request->getRequestUri())) {
+        return;
+      }
+
       $headers = [
         'X-Redirect-ID' => $redirect->id(),
       ];
diff --git a/src/Form/RedirectForm.php b/src/Form/RedirectForm.php
index 0c9eafd..05195f1 100644
--- a/src/Form/RedirectForm.php
+++ b/src/Form/RedirectForm.php
@@ -120,18 +120,14 @@ class RedirectForm extends ContentEntityForm {
       // Do nothing, we want to only compare the resulting URLs.
     }
 
-    $parsed_url = UrlHelper::parse(trim($source['path']));
-    $path = isset($parsed_url['path']) ? $parsed_url['path'] : NULL;
-    $query = isset($parsed_url['query']) ? $parsed_url['query'] : NULL;
-    $hash = Redirect::generateHash($path, $query, $form_state->getValue('language')[0]['value']);
-
     // Search for duplicate.
-    $redirects = \Drupal::entityManager()
-      ->getStorage('redirect')
-      ->loadByProperties(['hash' => $hash]);
+    $parsed_url = UrlHelper::parse(trim($source['path']));
+    $path = isset($parsed_url['path']) ? $parsed_url['path'] : '';
+    $query = isset($parsed_url['query']) ? $parsed_url['query'] : [];
+    $language = $form_state->getValue('language')[0]['value'];
+    $redirect = \Drupal::service('redirect.repository')->findMatchingRedirect($path, $query, $language);
 
-    if (!empty($redirects)) {
-      $redirect = array_shift($redirects);
+    if (!empty($redirect)) {
       if ($this->entity->isNew() || $redirect->id() != $this->entity->id()) {
         $form_state->setErrorByName('redirect_source', $this->t('The source path %source is already being redirected. Do you want to <a href="@edit-page">edit the existing redirect</a>?',
           [
diff --git a/src/RedirectRepository.php b/src/RedirectRepository.php
index 236c927..42311a4 100644
--- a/src/RedirectRepository.php
+++ b/src/RedirectRepository.php
@@ -6,6 +6,7 @@ use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Entity\EntityManagerInterface;
 use Drupal\Core\Language\Language;
+use Drupal\Core\Language\LanguageInterface;
 use Drupal\redirect\Entity\Redirect;
 use Drupal\redirect\Exception\RedirectLoopException;
 
@@ -69,6 +70,15 @@ class RedirectRepository {
       $hashes[] = Redirect::generateHash($source_path, $query, Language::LANGCODE_NOT_SPECIFIED);
     }
 
+    // The source path might be an alias, so add the source for the alias if it
+    // is. The alias manager will return the source path as is if it's not an
+    // alias, which will lead to a duplicate it in the hashes array, deal with
+    // that too.
+    $alias_language = ($language == Language::LANGCODE_NOT_SPECIFIED) ? NULL : $language;
+    $alias_source = ltrim(\Drupal::service('path.alias_manager')->getPathByAlias('/' . $source_path, $alias_language), '/');
+    $hashes[] = Redirect::generateHash($alias_source, $query, Language::LANGCODE_NOT_SPECIFIED);
+    $hashes = array_unique($hashes);
+
     // Add a hash without the query string if using passthrough querystrings.
     if (!empty($query) && $this->config->get('passthrough_querystring')) {
       $hashes[] = Redirect::generateHash($source_path, [], $language);