diff --git a/Changelog.md b/Changelog.md
--- a/Changelog.md
+++ b/Changelog.md
@@ -1,5 +1,10 @@
 # Revision history for network-control
 
+## 0.1.2
+
+* introducing a minimum size for window update
+  [#5](https://github.com/kazu-yamamoto/network-control/pull/5)
+
 ## 0.1.1
 
 * Change defaultMaxData
diff --git a/Network/Control/Flow.hs b/Network/Control/Flow.hs
--- a/Network/Control/Flow.hs
+++ b/Network/Control/Flow.hs
@@ -120,8 +120,9 @@
 
 -- | When an application consumed received data, this function should
 --   be called to update 'rxfConsumed'. If the available buffer size
---   is less than the half of the total buffer size.
---   the representation of window size update is returned.
+--   is less than the half of the total buffer size AND window size update
+--   is greater than 1/8 of the the total buffer size,
+--   the representation of the window size update is returned.
 --
 -- @
 -- Example:
@@ -162,15 +163,14 @@
     -> (RxFlow, Maybe Int)
     -- ^ 'Just' if the size should be informed to the peer.
 maybeOpenRxWindow consumed fct flow@RxFlow{..}
-    | available < threshold =
-        let rxfLimit' = consumed' + rxfBufSize
-            flow' =
+    | available < threshold && winUpdate > minSize =
+        let flow' =
                 flow
                     { rxfConsumed = consumed'
                     , rxfLimit = rxfLimit'
                     }
             update = case fct of
-                FCTWindowUpdate -> rxfLimit' - rxfLimit
+                FCTWindowUpdate -> winUpdate
                 FCTMaxData -> rxfLimit'
          in (flow', Just update)
     | otherwise =
@@ -179,7 +179,10 @@
   where
     available = rxfLimit - rxfReceived
     threshold = rxfBufSize `unsafeShiftR` 1
+    minSize = rxfBufSize `unsafeShiftR` 3
     consumed' = rxfConsumed + consumed
+    rxfLimit' = consumed' + rxfBufSize
+    winUpdate = rxfLimit' - rxfLimit
 
 -- | Checking if received data is acceptable against the
 --   current window.
diff --git a/network-control.cabal b/network-control.cabal
--- a/network-control.cabal
+++ b/network-control.cabal
@@ -1,6 +1,6 @@
 cabal-version:   3.0
 name:            network-control
-version:         0.1.1
+version:         0.1.2
 license:         BSD-3-Clause
 license-file:    LICENSE
 maintainer:      kazu@iij.ad.jp