diff --git a/tests/activities/models/test_post.py b/tests/activities/models/test_post.py
index 825a3bb17..2860b2a72 100644
--- a/tests/activities/models/test_post.py
+++ b/tests/activities/models/test_post.py
@@ -13,6 +13,7 @@ def test_fetch_post(httpx_mock: HTTPXMock, config_system):
     """
     httpx_mock.add_response(
         url="https://example.com/test-actor",
+        headers={"Content-Type": "application/activity+json"},
         json={
             "@context": [
                 "https://www.w3.org/ns/activitystreams",
@@ -23,6 +24,7 @@ def test_fetch_post(httpx_mock: HTTPXMock, config_system):
     )
     httpx_mock.add_response(
         url="https://example.com/test-post",
+        headers={"Content-Type": "application/activity+json"},
         json={
             "@context": [
                 "https://www.w3.org/ns/activitystreams",
diff --git a/tests/api/test_search.py b/tests/api/test_search.py
index 36a5c0a92..dabb4c86c 100644
--- a/tests/api/test_search.py
+++ b/tests/api/test_search.py
@@ -86,7 +86,7 @@ def test_search_not_found(httpx_mock: HTTPXMock, api_client):
 @pytest.mark.parametrize(
     "content_type",
     [
-        "application/ld+json",
+        'application/ld+json; profile="https://www.w3.org/ns/activitystreams"',
         "application/activity+json",
     ],
 )
diff --git a/tests/users/models/test_identity.py b/tests/users/models/test_identity.py
index 3b8ac356f..c83e2e4c6 100644
--- a/tests/users/models/test_identity.py
+++ b/tests/users/models/test_identity.py
@@ -109,6 +109,7 @@ def test_fetch_actor(httpx_mock, config_system):
     # Trigger actor fetch
     httpx_mock.add_response(
         url="https://example.com/.well-known/webfinger?resource=acct:test@example.com",
+        headers={"Content-Type": "application/activity+json"},
         json={
             "subject": "acct:test@example.com",
             "aliases": [
@@ -130,6 +131,7 @@ def test_fetch_actor(httpx_mock, config_system):
     )
     httpx_mock.add_response(
         url="https://example.com/test-actor/",
+        headers={"Content-Type": "application/activity+json"},
         json={
             "@context": [
                 "https://www.w3.org/ns/activitystreams",
@@ -170,6 +172,7 @@ def test_fetch_actor(httpx_mock, config_system):
     )
     httpx_mock.add_response(
         url="https://example.com/test-actor/collections/featured/",
+        headers={"Content-Type": "application/activity+json"},
         json={
             "type": "Collection",
             "totalItems": 1,