diff --git a/src/httpcore2/httpcore2/_async/http2.py b/src/httpcore2/httpcore2/_async/http2.py
index 0022a2b6..6f009c13 100644
--- a/src/httpcore2/httpcore2/_async/http2.py
+++ b/src/httpcore2/httpcore2/_async/http2.py
@@ -246,10 +246,11 @@ async def _send_stream_data(self, request: Request, stream_id: int, data: bytes)
         """
         Send a single chunk of data in one or more data frames.
         """
-        while data:
+        position = 0
+        while position < len(data):
             max_flow = await self._wait_for_outgoing_flow(request, stream_id)
-            chunk_size = min(len(data), max_flow)
-            chunk, data = data[:chunk_size], data[chunk_size:]
+            chunk = data[position : position + max_flow]
+            position += len(chunk)
             self._h2_state.send_data(stream_id, chunk)
             await self._write_outgoing_data(request)
 
diff --git a/src/httpcore2/httpcore2/_sync/http2.py b/src/httpcore2/httpcore2/_sync/http2.py
index 3b79af8c..ee314c8a 100644
--- a/src/httpcore2/httpcore2/_sync/http2.py
+++ b/src/httpcore2/httpcore2/_sync/http2.py
@@ -246,10 +246,11 @@ def _send_stream_data(self, request: Request, stream_id: int, data: bytes) -> No
         """
         Send a single chunk of data in one or more data frames.
         """
-        while data:
+        position = 0
+        while position < len(data):
             max_flow = self._wait_for_outgoing_flow(request, stream_id)
-            chunk_size = min(len(data), max_flow)
-            chunk, data = data[:chunk_size], data[chunk_size:]
+            chunk = data[position : position + max_flow]
+            position += len(chunk)
             self._h2_state.send_data(stream_id, chunk)
             self._write_outgoing_data(request)