diff --git a/config.yaml.dist b/config.yaml.dist
index a38393a0..1f4a2307 100644
--- a/config.yaml.dist
+++ b/config.yaml.dist
@@ -36,6 +36,7 @@ smtp:
 elasticsearch:
     host: localhost
     port: 9200
+    index: szurubooru
 
 limits:
     users_per_page: 20
diff --git a/server/szurubooru/func/image_hash.py b/server/szurubooru/func/image_hash.py
index 8f8c4d72..ae368488 100644
--- a/server/szurubooru/func/image_hash.py
+++ b/server/szurubooru/func/image_hash.py
@@ -12,7 +12,10 @@ es = elasticsearch.Elasticsearch([{
     'host': config.config['elasticsearch']['host'],
     'port': config.config['elasticsearch']['port'],
 }])
-session = SignatureES(es, index='szurubooru')
+
+
+def _get_session():
+    return SignatureES(es, index=config.config['elasticsearch']['index'])
 
 
 def _safe_blanket(default_param_factory):
@@ -48,6 +51,7 @@ class Lookalike:
 def add_image(path, image_content):
     if not path or not image_content:
         return
+    session = _get_session()
     session.add_image(path=path, img=image_content, bytestream=True)
 
 
@@ -55,6 +59,7 @@ def add_image(path, image_content):
 def delete_image(path):
     if not path:
         return
+    session = _get_session()
     es.delete_by_query(
         index=session.index,
         doc_type=session.doc_type,
@@ -64,6 +69,7 @@ def delete_image(path):
 @_safe_blanket(lambda: [])
 def search_by_image(image_content):
     ret = []
+    session = _get_session()
     for result in session.search_image(
             path=image_content,  # sic
             bytestream=True):
@@ -76,6 +82,7 @@ def search_by_image(image_content):
 
 @_safe_blanket(lambda: None)
 def purge():
+    session = _get_session()
     es.delete_by_query(
         index=session.index,
         doc_type=session.doc_type,
@@ -84,6 +91,7 @@ def purge():
 
 @_safe_blanket(lambda: set())
 def get_all_paths():
+    session = _get_session()
     search = (
         elasticsearch_dsl.Search(
             using=es, index=session.index, doc_type=session.doc_type)
diff --git a/server/szurubooru/tests/api/test_post_creating.py b/server/szurubooru/tests/api/test_post_creating.py
index 341990c8..9737a73b 100644
--- a/server/szurubooru/tests/api/test_post_creating.py
+++ b/server/szurubooru/tests/api/test_post_creating.py
@@ -258,7 +258,8 @@ def test_omitting_optional_field(
 
 
 def test_errors_not_spending_ids(
-        config_injector, tmpdir, context_factory, read_asset, user_factory):
+        config_injector, tmpdir, context_factory, read_asset, user_factory,
+        skip_post_hashing):
     config_injector({
         'data_dir': str(tmpdir.mkdir('data')),
         'data_url': 'example.com',
diff --git a/server/szurubooru/tests/assets/jpeg-similar.jpg b/server/szurubooru/tests/assets/jpeg-similar.jpg
new file mode 100644
index 00000000..af612092
Binary files /dev/null and b/server/szurubooru/tests/assets/jpeg-similar.jpg differ
diff --git a/server/szurubooru/tests/conftest.py b/server/szurubooru/tests/conftest.py
index 5dd47576..db34ee02 100644
--- a/server/szurubooru/tests/conftest.py
+++ b/server/szurubooru/tests/conftest.py
@@ -155,7 +155,7 @@ def tag_factory():
     return factory
 
 
-@pytest.yield_fixture(autouse=True)
+@pytest.yield_fixture
 def skip_post_hashing():
     with patch('szurubooru.func.image_hash.add_image'), \
             patch('szurubooru.func.image_hash.delete_image'):
@@ -163,7 +163,7 @@ def skip_post_hashing():
 
 
 @pytest.fixture
-def post_factory():
+def post_factory(skip_post_hashing):
     # pylint: disable=invalid-name
     def factory(
             id=None,
diff --git a/server/szurubooru/tests/func/test_image_hash.py b/server/szurubooru/tests/func/test_image_hash.py
new file mode 100644
index 00000000..3bbdeba2
--- /dev/null
+++ b/server/szurubooru/tests/func/test_image_hash.py
@@ -0,0 +1,24 @@
+from time import sleep
+from szurubooru.func import image_hash
+
+
+def test_hashing(read_asset, config_injector):
+    config_injector({'elasticsearch': {'index': 'szurubooru_test'}})
+    image_hash.purge()
+    image_hash.add_image('test', read_asset('jpeg.jpg'))
+
+    sleep(0.1)
+
+    paths = image_hash.get_all_paths()
+    results_exact = image_hash.search_by_image(read_asset('jpeg.jpg'))
+    results_similar = image_hash.search_by_image(read_asset('jpeg-similar.jpg'))
+
+    assert len(paths) == 1
+    assert len(results_exact) == 1
+    assert len(results_similar) == 1
+    assert results_exact[0].path == 'test'
+    assert results_exact[0].score == 63
+    assert results_exact[0].distance == 0
+    assert results_similar[0].path == 'test'
+    assert results_similar[0].score == 26
+    assert abs(results_similar[0].distance - 0.189390583) < 1e-8
diff --git a/server/szurubooru/tests/func/test_posts.py b/server/szurubooru/tests/func/test_posts.py
index f44fb03b..a10cc6d9 100644
--- a/server/szurubooru/tests/func/test_posts.py
+++ b/server/szurubooru/tests/func/test_posts.py
@@ -290,15 +290,8 @@ def test_update_post_source_with_too_long_string():
         ),
     ])
 def test_update_post_content_for_new_post(
-        tmpdir,
-        config_injector,
-        post_factory,
-        read_asset,
-        is_existing,
-        input_file,
-        expected_mime_type,
-        expected_type,
-        output_file_name):
+        tmpdir, config_injector, post_factory, read_asset, is_existing,
+        input_file, expected_mime_type, expected_type, output_file_name):
     with patch('szurubooru.func.util.get_sha1'):
         util.get_sha1.return_value = 'crc'
         config_injector({