diff --git a/CHANGELOG.md b/CHANGELOG.md
index 71df2eea2..f1a957882 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,8 @@
 
 ## Unreleased: mitmproxy next
 
+- Flush flow file after each flow to allow further processing.
+  ([#7967](https://github.com/mitmproxy/mitmproxy/pull/7967), @caiquejjx)
 - infer_content_encoding: Fallback to UTF-8 for more content types
   ([#7961](https://github.com/mitmproxy/mitmproxy/pull/7961), @xu-cheng)
 - Remove `bless` from hex editors to avoid issues with macOS
diff --git a/mitmproxy/io/io.py b/mitmproxy/io/io.py
index 579bd9e96..af89577d9 100644
--- a/mitmproxy/io/io.py
+++ b/mitmproxy/io/io.py
@@ -82,7 +82,7 @@ class FlowReader:
 
 
 class FilteredFlowWriter:
-    def __init__(self, fo, flt):
+    def __init__(self, fo: BinaryIO, flt: flowfilter.TFilter | None):
         self.fo = fo
         self.flt = flt
 
@@ -91,6 +91,7 @@ class FilteredFlowWriter:
             return
         d = f.get_state()
         tnetstring.dump(d, self.fo)
+        self.fo.flush()
 
 
 def read_flows_from_paths(paths) -> list[flow.Flow]: