diff --git a/tina4_python/Webserver.py b/tina4_python/Webserver.py
index ebb795e..bc8953a 100644
--- a/tina4_python/Webserver.py
+++ b/tina4_python/Webserver.py
@@ -317,7 +317,17 @@ async def get_response(self, method: str, scope ,reader: asyncio.StreamReader, w
             self.send_header("Access-Control-Allow-Credentials", "true", headers)
 
             headers_bytes = await self.get_headers(headers, self.response_protocol, HTTP_OK)
-            return headers_bytes if not asgi_response else (None, headers)
+            class _Tina4Response:
+                def __init__(self, content: str = "", http_code: int = HTTP_OK, content_type: str = "text/plain", headers: dict | None = None):
+                    self.content = content
+                    self.http_code = http_code
+                    self.content_type = content_type
+                    self.headers = headers or {}
+
+            if not asgi_response:
+                return headers_bytes
+
+            return _Tina4Response(content="", http_code=HTTP_OK, content_type="text/plain", headers={}), headers
 
         # ------------------------------------------------------------------
         # Query string parsing with nested support
@@ -592,4 +602,4 @@ def server_close(self):
         """
         if self.server:
             self.server.close()
-            self.running = False
\ No newline at end of file
+            self.running = False
diff --git a/tina4_python/__init__.py b/tina4_python/__init__.py
index 7ad2552..052ea40 100644
--- a/tina4_python/__init__.py
+++ b/tina4_python/__init__.py
@@ -413,8 +413,19 @@ async def app(scope, receive, send):
             if message["type"] != "websocket":
                 response_headers = []
                 for header in tina4_headers:
-                    header = header.split(":")
-                    response_headers.append([header[0].strip().encode(), header[1].strip().encode()])
+                    # ensure header is a str
+                    if isinstance(header, bytes):
+                        header = header.decode()
+                    else:
+                        header = str(header)
+
+                    # split only on the first ':' to preserve ':' in values (e.g. URLs with ports)
+                    name, sep, value = header.partition(":")
+                    if not sep:
+                        # malformed header, skip it
+                        continue
+
+                    response_headers.append([name.strip().encode(), value.lstrip().encode()])
 
                 await send({
                     'type': 'http.response.start',