diff --git a/application/bookmark/Bookmark.php b/application/bookmark/Bookmark.php
index 56751e15d..6a83bef00 100644
--- a/application/bookmark/Bookmark.php
+++ b/application/bookmark/Bookmark.php
@@ -505,7 +505,7 @@ public function getAdditionalContentEntry(string $key, $default = null)
     }
 
     /**
-     * Rename a tag in tags list.
+     * Rename a tag in tags list. If the new tag already exists, merge them
      *
      * @param string $fromTag
      * @param string $toTag
@@ -513,7 +513,11 @@ public function getAdditionalContentEntry(string $key, $default = null)
     public function renameTag(string $fromTag, string $toTag): void
     {
         if (($pos = array_search($fromTag, $this->tags ?? [])) !== false) {
-            $this->tags[$pos] = trim($toTag);
+            if (in_array($toTag, $this->tags ?? []) !== false) {
+                $this->deleteTag($fromTag);
+            } else {
+                $this->tags[$pos] = trim($toTag);
+            }
         }
     }
 
diff --git a/tests/bookmark/BookmarkTest.php b/tests/bookmark/BookmarkTest.php
index a6dc3cce2..41ed8aa55 100644
--- a/tests/bookmark/BookmarkTest.php
+++ b/tests/bookmark/BookmarkTest.php
@@ -374,6 +374,9 @@ public function testSetTags()
     public function testRenameTag()
     {
         $bookmark = new Bookmark();
+        $bookmark->renameTag('chair', 'table');
+        $this->assertEquals([], $bookmark->getTags());
+
         $bookmark->setTags(['tag1', 'tag2', 'chair']);
         $bookmark->renameTag('chair', 'table');
         $this->assertEquals(['tag1', 'tag2', 'table'], $bookmark->getTags());
diff --git a/tests/front/controller/admin/ManageTagControllerTest.php b/tests/front/controller/admin/ManageTagControllerTest.php
index 34a770a0c..b5c92fc17 100644
--- a/tests/front/controller/admin/ManageTagControllerTest.php
+++ b/tests/front/controller/admin/ManageTagControllerTest.php
@@ -13,7 +13,6 @@
 use Shaarli\TestCase;
 use Slim\Http\Request;
 use Slim\Http\Response;
-
 // These are declared for the bookmark service
 use malkusch\lock\mutex\NoMutex;
 use Shaarli\History;
@@ -56,8 +55,18 @@ public function setUp(): void
         self::$refDB = new ReferenceLinkDB();
         self::$refDB->write(self::$testDatastore);
         $history = new History('sandbox/history.php');
-        $this->container->bookmarkService = new FakeBookmarkService($conf, static::$pluginManager, $history, $mutex, true);
-        $this->linkFilter = new BookmarkFilter($this->container->bookmarkService->getBookmarks(), $conf, static::$pluginManager);
+        $this->container->bookmarkService = new FakeBookmarkService(
+            $conf,
+            static::$pluginManager,
+            $history,
+            $mutex,
+            true
+        );
+        $this->linkFilter = new BookmarkFilter(
+            $this->container->bookmarkService->getBookmarks(),
+            $conf,
+            static::$pluginManager
+        );
     }
 
     /**