diff --git a/pyinfra/utils/buffer.py b/pyinfra/utils/buffer.py
index 030f290..7127a12 100644
--- a/pyinfra/utils/buffer.py
+++ b/pyinfra/utils/buffer.py
@@ -1,13 +1,13 @@
 from collections import deque
 from typing import Any
 
-from funcy import lmap, repeatedly
+from funcy import repeatedly
 
 
 def bufferize(fn, buffer_size=3, persist_fn=lambda x: x):
     def buffered_fn(item: Any, final=False):
         buffer.append(persist_fn(item))
-        response_payload = lmap(fn, repeatedly(buffer.popleft, n_items_to_pop(buffer, final)))
+        response_payload = fn(repeatedly(buffer.popleft, n_items_to_pop(buffer, final)))
         return response_payload
 
     def buffer_full(current_buffer_size):
diff --git a/pyinfra/utils/func.py b/pyinfra/utils/func.py
index 059bfb3..8b7ed08 100644
--- a/pyinfra/utils/func.py
+++ b/pyinfra/utils/func.py
@@ -7,6 +7,10 @@ def lift(fn):
     return curry(map)(fn)
 
 
+def llift(fn):
+    return compose(list, lift(fn))
+
+
 def starlift(fn):
     return curry(starmap)(fn)
 
diff --git a/test/fixtures/server.py b/test/fixtures/server.py
index 6a7b6a8..e7c77b4 100644
--- a/test/fixtures/server.py
+++ b/test/fixtures/server.py
@@ -12,6 +12,7 @@ from waitress import serve
 
 from pyinfra.rest import wrap_operation
 from pyinfra.utils.buffer import bufferize
+from pyinfra.utils.func import lift, llift
 from test.server import set_up_processing_server
 from test.utils.image import image_to_bytes
 
@@ -43,12 +44,21 @@ def server(processor_fn):
 
 
 @pytest.fixture
-def processor_fn(operation, buffer_size):
-    return bufferize(wrap_operation(operation), buffer_size=buffer_size, persist_fn=attrgetter("json"))
+def processor_fn(operation, buffer_size, batched):
+
+    fn = wrap_operation(operation)
+
+    if not batched:
+        fn = llift(fn)
+
+    return bufferize(fn, buffer_size=buffer_size, persist_fn=attrgetter("json"))
 
 
 @pytest.fixture
 def operation(item_type):
+    def upper(string: bytes, metadata):
+        return string.decode().upper().encode(), metadata
+
     def rotate(im: bytes, metadata):
         im = Image.open(io.BytesIO(im))
         return image_to_bytes(im.rotate(90)), metadata
@@ -57,9 +67,6 @@ def operation(item_type):
         for page in fitz.open(stream=pdf):
             yield page.get_pixmap().tobytes("png"), metadata
 
-    def upper(string: bytes, metadata):
-        return string.decode().upper().encode(), metadata
-
     if item_type == "string":
         return upper
     elif item_type == "image":
@@ -75,6 +82,11 @@ def item_type(request):
     return request.param
 
 
+@pytest.fixture(params=[False])
+def batched(request):
+    """Controls, whether the buffer processor function of the webserver is applied to batches or single items."""
+    return request.param
+
 @pytest.fixture(params=[1, 3, 7, 100])
 def buffer_size(request):
     return request.param