diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,10 @@
 # Changelog for unliftio
 
+## 0.2.22.0
+
+* Add `UnliftIO.STM.flushTBQueue`
+* Add `UnliftIO.STM.lengthTBQueue`
+
 ## 0.2.21.0
 
 * Add `UnliftIO.Directory.createDirectoryLink`
diff --git a/src/UnliftIO/STM.hs b/src/UnliftIO/STM.hs
--- a/src/UnliftIO/STM.hs
+++ b/src/UnliftIO/STM.hs
@@ -73,10 +73,12 @@
   , newTBQueueIO
   , STM.readTBQueue
   , STM.tryReadTBQueue
+  , STM.flushTBQueue
   , STM.peekTBQueue
   , STM.tryPeekTBQueue
   , STM.writeTBQueue
   , STM.unGetTBQueue
+  , STM.lengthTBQueue
   , STM.isEmptyTBQueue
   , STM.isFullTBQueue
   ) where
diff --git a/unliftio.cabal b/unliftio.cabal
--- a/unliftio.cabal
+++ b/unliftio.cabal
@@ -5,7 +5,7 @@
 -- see: https://github.com/sol/hpack
 
 name:           unliftio
-version:        0.2.21.0
+version:        0.2.22.0
 synopsis:       The MonadUnliftIO typeclass for unlifting monads to IO (batteries included)
 description:    Please see the documentation and README at <https://www.stackage.org/package/unliftio>
 category:       Control
@@ -55,7 +55,7 @@
     , directory
     , filepath
     , process >=1.2.0.0
-    , stm >=2.4.3
+    , stm >=2.5
     , time
     , transformers
     , unliftio-core >=0.1.1.0
@@ -110,7 +110,7 @@
     , filepath
     , hspec
     , process >=1.2.0.0
-    , stm >=2.4.3
+    , stm >=2.5
     , time
     , transformers
     , unliftio
@@ -139,7 +139,7 @@
     , filepath
     , gauge
     , process >=1.2.0.0
-    , stm >=2.4.3
+    , stm >=2.5
     , time
     , transformers
     , unliftio