diff --git a/taiga/projects/history/migrations/0005_auto_20141120_1119.py b/taiga/projects/history/migrations/0005_auto_20141120_1119.py
new file mode 100644
index 00000000..72489aad
--- /dev/null
+++ b/taiga/projects/history/migrations/0005_auto_20141120_1119.py
@@ -0,0 +1,19 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import models, migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('history', '0004_historyentry_is_hidden'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='historyentry',
+            name='key',
+            field=models.CharField(default=None, blank=True, max_length=255, db_index=True, null=True),
+        ),
+    ]
diff --git a/taiga/projects/history/models.py b/taiga/projects/history/models.py
index ec79f91f..0cf9d0e5 100644
--- a/taiga/projects/history/models.py
+++ b/taiga/projects/history/models.py
@@ -48,7 +48,7 @@ class HistoryEntry(models.Model):
     user = JsonField(blank=True, default=None, null=True)
     created_at = models.DateTimeField(default=timezone.now)
     type = models.SmallIntegerField(choices=HISTORY_TYPE_CHOICES)
-    key = models.CharField(max_length=255, null=True, default=None, blank=True)
+    key = models.CharField(max_length=255, null=True, default=None, blank=True, db_index=True)
 
     # Stores the last diff
     diff = JsonField(null=True, default=None)