diff --git a/openedx_tagging/core/tagging/admin.py b/openedx_tagging/core/tagging/admin.py
index 5be444cfc..4016df6ef 100644
--- a/openedx_tagging/core/tagging/admin.py
+++ b/openedx_tagging/core/tagging/admin.py
@@ -1,10 +1,44 @@
 """
 Tagging app admin
 """
+from __future__ import annotations
+
 from django.contrib import admin
 
 from .models import ObjectTag, Tag, Taxonomy
 
 admin.site.register(Taxonomy)
-admin.site.register(Tag)
-admin.site.register(ObjectTag)
+
+
+@admin.register(Tag)
+class TagAdmin(admin.ModelAdmin):
+    """
+    Admin definition for Tag model
+    """
+    autocomplete_fields = ["parent"]
+    search_fields = ["value", "external_id"]
+    list_display = ["__str__", "taxonomy", "external_id"]
+    list_filter = ["taxonomy"]
+
+    def has_add_permission(self, request):
+        """
+        Don't create Tags using the django admin. Use the API or UI.
+        """
+        return False
+
+
+@admin.register(ObjectTag)
+class ObjectTagAdmin(admin.ModelAdmin):
+    """
+    Admin definition for ObjectTag model
+    """
+    fields = ["object_id", "taxonomy", "tag", "_value"]
+    autocomplete_fields = ["tag"]
+    list_display = ["object_id", "name", "value"]
+    readonly_fields = ["object_id"]
+
+    def has_add_permission(self, request):
+        """
+        Don't create ObjectTags using the django admin. Use the API or UI.
+        """
+        return False
diff --git a/openedx_tagging/core/tagging/migrations/0014_minor_fixes.py b/openedx_tagging/core/tagging/migrations/0014_minor_fixes.py
new file mode 100644
index 000000000..e09177899
--- /dev/null
+++ b/openedx_tagging/core/tagging/migrations/0014_minor_fixes.py
@@ -0,0 +1,36 @@
+# Generated by Django 3.2.22 on 2023-11-08 22:37
+
+from django.db import migrations, models
+
+import openedx_learning.lib.fields
+
+
+def fix_language_taxonomy(apps, schema_editor):
+    """
+    Ensure that the language taxonomy has the correct taxonomy_class. Some
+    previous versions of this app's migration history allowed it to be created
+    without the right taxonomy_class.
+    """
+    Taxonomy = apps.get_model("oel_tagging", "Taxonomy")
+    correct_class = "openedx_tagging.core.tagging.models.system_defined.LanguageTaxonomy"
+    lang_taxonomy = Taxonomy.objects.get(pk=-1)
+    if lang_taxonomy._taxonomy_class != correct_class:
+        lang_taxonomy._taxonomy_class = correct_class
+        lang_taxonomy.save(update_fields=["_taxonomy_class"])
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('oel_tagging', '0013_tag_parent_blank'),
+    ]
+
+    operations = [
+        # Allow taxonomy_class to be blank:
+        migrations.AlterField(
+            model_name='taxonomy',
+            name='_taxonomy_class',
+            field=models.CharField(blank=True, help_text='Taxonomy subclass used to instantiate this instance; must be a fully-qualified module and class name. If the module/class cannot be imported, an error is logged and the base Taxonomy class is used instead.', max_length=255, null=True),
+        ),
+        migrations.RunPython(fix_language_taxonomy, None),
+    ]
diff --git a/openedx_tagging/core/tagging/models/base.py b/openedx_tagging/core/tagging/models/base.py
index 86f948770..f79bb2522 100644
--- a/openedx_tagging/core/tagging/models/base.py
+++ b/openedx_tagging/core/tagging/models/base.py
@@ -227,6 +227,7 @@ class Taxonomy(models.Model):
             "Taxonomy subclass used to instantiate this instance; must be a fully-qualified module and class name."
             " If the module/class cannot be imported, an error is logged and the base Taxonomy class is used instead."
         ),
+        blank=True,
     )
 
     class Meta:
diff --git a/openedx_tagging/core/tagging/rest_api/v1/views.py b/openedx_tagging/core/tagging/rest_api/v1/views.py
index d2566ca2c..e2145200f 100644
--- a/openedx_tagging/core/tagging/rest_api/v1/views.py
+++ b/openedx_tagging/core/tagging/rest_api/v1/views.py
@@ -170,7 +170,8 @@ class TaxonomyView(ModelViewSet):
 
     """
 
-    lookup_value_regex = r"\d+"
+    # System taxonomies use negative numbers for their primary keys
+    lookup_value_regex = r'-?\d+'
     serializer_class = TaxonomySerializer
     permission_classes = [TaxonomyObjectPermissions]
 
diff --git a/tests/openedx_tagging/core/tagging/test_views.py b/tests/openedx_tagging/core/tagging/test_views.py
index bdb214aed..1a1c69ada 100644
--- a/tests/openedx_tagging/core/tagging/test_views.py
+++ b/tests/openedx_tagging/core/tagging/test_views.py
@@ -169,6 +169,24 @@ def test_list_invalid_page(self) -> None:
 
         assert response.status_code == status.HTTP_404_NOT_FOUND
 
+    def test_language_taxonomy(self):
+        """
+        Test the "Language" taxonomy that's included.
+        """
+        self.client.force_authenticate(user=self.user)
+        response = self.client.get(TAXONOMY_LIST_URL)
+        assert response.status_code == status.HTTP_200_OK
+        taxonomy_list = response.data["results"]
+        assert len(taxonomy_list) == 1
+        check_taxonomy(
+            taxonomy_list[0],
+            taxonomy_id=LANGUAGE_TAXONOMY_ID,
+            name="Languages",
+            description="Languages that are enabled on this system.",
+            allow_multiple=False,  # We may change this in the future to allow multiple language tags
+            system_defined=True,
+        )
+
     @ddt.data(
         (None, {"enabled": True}, status.HTTP_401_UNAUTHORIZED),
         (None, {"enabled": False}, status.HTTP_401_UNAUTHORIZED),
@@ -193,6 +211,13 @@ def test_detail_taxonomy(self, user_attr: str | None, taxonomy_data: dict[str, b
         if status.is_success(expected_status):
             check_taxonomy(response.data, taxonomy.pk, **create_data)
 
+    def test_detail_system_taxonomy(self):
+        url = TAXONOMY_DETAIL_URL.format(pk=LANGUAGE_TAXONOMY_ID)
+        self.client.force_authenticate(user=self.user)
+
+        response = self.client.get(url)
+        assert response.status_code == status.HTTP_200_OK
+
     def test_detail_taxonomy_404(self) -> None:
         url = TAXONOMY_DETAIL_URL.format(pk=123123)