diff --git a/src/posit/connect/_api_call.py b/src/posit/connect/_api_call.py
index 5d652a28..fb40352d 100644
--- a/src/posit/connect/_api_call.py
+++ b/src/posit/connect/_api_call.py
@@ -16,7 +16,7 @@ def _endpoint(self, *path) -> str: ...
     def _get_api(self, *path) -> Any: ...
     def _delete_api(self, *path) -> Any | None: ...
     def _patch_api(self, *path, json: Any | None) -> Any: ...
-    def _post_api(self, *path, json: Any | None) -> Any: ...
+    def _post_api(self, *path, json: Any | None) -> Any | None: ...
     def _put_api(self, *path, json: Any | None) -> Any: ...
 
 
@@ -68,14 +68,18 @@ def _post_api(
         self: ApiCallProtocol,
         *path,
         json: Any | None,
-    ) -> Any:
+    ) -> Any | None:
         response = self._ctx.session.post(self._endpoint(*path), json=json)
+        if len(response.content) == 0:
+            return None
         return response.json()
 
     def _put_api(
         self: ApiCallProtocol,
         *path,
         json: Any | None,
-    ) -> Any:
+    ) -> Any | None:
         response = self._ctx.session.put(self._endpoint(*path), json=json)
+        if len(response.content) == 0:
+            return None
         return response.json()
diff --git a/src/posit/connect/oauth/integrations.py b/src/posit/connect/oauth/integrations.py
index 085eedd6..0aabc8ab 100644
--- a/src/posit/connect/oauth/integrations.py
+++ b/src/posit/connect/oauth/integrations.py
@@ -123,6 +123,7 @@ def create(self, **kwargs) -> Integration:
         Integration
         """
         result = self._post_api(json=kwargs)
+        assert result is not None, "Integration creation failed"
         return Integration(self._ctx, **result)
 
     def find(self) -> List[Integration]:
diff --git a/src/posit/connect/permissions.py b/src/posit/connect/permissions.py
index 62d428a7..e873d66d 100644
--- a/src/posit/connect/permissions.py
+++ b/src/posit/connect/permissions.py
@@ -66,6 +66,7 @@ def update(self, *args, **kwargs) -> Permission:
         body.update(dict(*args))
         body.update(**kwargs)
         result = self._put_api(json=body)
+        assert result is not None, "Permission update failed."
         return Permission(self._ctx, **result)
 
 
diff --git a/src/posit/connect/users.py b/src/posit/connect/users.py
index 90f97276..94b0ffb6 100644
--- a/src/posit/connect/users.py
+++ b/src/posit/connect/users.py
@@ -232,6 +232,7 @@ def update(
         >>> user.update(first_name="Jane", last_name="Smith")
         """
         result = self._put_api(json=kwargs)
+        assert result is not None, "User update failed."
 
         return User(self._ctx, **result)
 
@@ -315,6 +316,7 @@ def create(self, **attributes: Unpack[_CreateUser]) -> User:
         """
         # todo - use the 'context' module to inspect the 'authentication' object and route to POST (local) or PUT (remote).
         result = self._post_api(json=attributes)
+        assert result is not None, "User creation failed."
         return User(self._ctx, **result)
 
     class _FindUser(TypedDict):
diff --git a/tests/posit/connect/test_users.py b/tests/posit/connect/test_users.py
index 4905ca74..a2c55727 100644
--- a/tests/posit/connect/test_users.py
+++ b/tests/posit/connect/test_users.py
@@ -67,7 +67,6 @@ def test_lock(self):
         responses.post(
             "https://connect.example/__api__/v1/users/a1b2c3d4-e5f6-g7h8-i9j0-k1l2m3n4o5p6/lock",
             match=[responses.matchers.json_params_matcher({"locked": True})],
-            json={},
         )
         locked_user = user.lock()
         assert locked_user["locked"]
@@ -89,7 +88,6 @@ def test_lock_self_true(self):
         responses.post(
             "https://connect.example/__api__/v1/users/20a79ce3-6e87-4522-9faf-be24228800a4/lock",
             match=[responses.matchers.json_params_matcher({"locked": True})],
-            json={},
         )
         unlocked_user = user.lock(force=True)
         assert unlocked_user["locked"]
@@ -131,7 +129,6 @@ def test_unlock(self):
         responses.post(
             "https://connect.example/__api__/v1/users/20a79ce3-6e87-4522-9faf-be24228800a4/lock",
             match=[responses.matchers.json_params_matcher({"locked": False})],
-            json={},
         )
         unlocked_user = user.unlock()
         assert not unlocked_user["locked"]