diff --git a/bookmarks/services/tags.py b/bookmarks/services/tags.py
index 3c13f9e..d79a7fe 100644
--- a/bookmarks/services/tags.py
+++ b/bookmarks/services/tags.py
@@ -1,3 +1,4 @@
+import logging
 import operator
 from typing import List
 
@@ -7,6 +8,8 @@ from django.utils import timezone
 from bookmarks.models import Tag
 from bookmarks.utils import unique
 
+logger = logging.getLogger(__name__)
+
 
 def get_or_create_tags(tag_names: List[str], user: User):
     tags = [get_or_create_tag(tag_name, user) for tag_name in tag_names]
@@ -21,3 +24,14 @@ def get_or_create_tag(name: str, user: User):
         tag.date_added = timezone.now()
         tag.save()
         return tag
+    except Tag.MultipleObjectsReturned:
+        # Legacy databases might contain duplicate tags with different capitalization
+        first_tag = Tag.objects.filter(name__iexact=name, owner=user).first()
+        message = (
+            "Found multiple tags for the name '{0}' with different capitalization. "
+            "Using the first tag with the name '{1}'. "
+            "Since v.1.2 tags work case-insensitive, which means duplicates of the same name are not allowed anymore. "
+            "To solve this error remove the duplicate tag in admin."
+        ).format(name, first_tag.name)
+        logger.error(message)
+        return first_tag
diff --git a/bookmarks/tests/test_tags_service.py b/bookmarks/tests/test_tags_service.py
index 297385d..038df2c 100644
--- a/bookmarks/tests/test_tags_service.py
+++ b/bookmarks/tests/test_tags_service.py
@@ -42,6 +42,13 @@ class TagTestCase(TestCase):
         self.assertEqual(len(tags), 1)
         self.assertEqual(first_tag.id, second_tag.id)
 
+    def test_get_or_create_tag_should_handle_legacy_dbs_with_existing_duplicates(self):
+        Tag.objects.create(name='book', date_added=timezone.now(), owner=self.user)
+        Tag.objects.create(name='Book', date_added=timezone.now(), owner=self.user)
+        first_tag = get_or_create_tag('Book', self.user)
+
+        self.assertEqual(first_tag.id, first_tag.id)
+
     def test_get_or_create_tags_should_return_tags(self):
         books_tag = get_or_create_tag('Book', self.user)
         movies_tag = get_or_create_tag('Movie', self.user)
diff --git a/siteroot/settings/dev.py b/siteroot/settings/dev.py
index 5aed862..28f50e1 100644
--- a/siteroot/settings/dev.py
+++ b/siteroot/settings/dev.py
@@ -12,21 +12,25 @@ DEBUG = True
 SASS_PROCESSOR_ENABLED = True
 
 # Enable debug logging
-# Logging with SQL statements
 LOGGING = {
     'version': 1,
-    'filters': {
-        'require_debug_true': {
-            '()': 'django.utils.log.RequireDebugTrue',
-        }
+    'disable_existing_loggers': False,
+    'formatters': {
+        'simple': {
+            'format': '{levelname} {message}',
+            'style': '{',
+        },
     },
     'handlers': {
         'console': {
-            'level': 'DEBUG',
-            'filters': ['require_debug_true'],
             'class': 'logging.StreamHandler',
+            'formatter': 'simple'
         }
     },
+    'root': {
+        'handlers': ['console'],
+        'level': 'WARNING',
+    },
     'loggers': {
         'django.db.backends': {
             'level': 'ERROR',  # Set to DEBUG to log all SQL calls