diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,8 +1,11 @@
 # Revsion history of io-classes
 
-## next release
+## 1.10.0.0
 
 ### Breaking changes
+
+* Added `flushEventLog` to `MonadEventLog` class.
+* Added `Monad` constraint to `MonadEventlog` class.
 
 ### Non-breaking changes
 
diff --git a/io-classes.cabal b/io-classes.cabal
--- a/io-classes.cabal
+++ b/io-classes.cabal
@@ -1,6 +1,6 @@
 cabal-version:       3.4
 name:                io-classes
-version:             1.9.0.0
+version:             1.10.0.0
 synopsis:            Type classes for concurrency with STM, ST and timing
 description:
   IO Monad class hierarchy compatible with:
diff --git a/io-classes/Control/Monad/Class/MonadEventlog.hs b/io-classes/Control/Monad/Class/MonadEventlog.hs
--- a/io-classes/Control/Monad/Class/MonadEventlog.hs
+++ b/io-classes/Control/Monad/Class/MonadEventlog.hs
@@ -2,7 +2,7 @@
 
 import Control.Monad.Reader
 
-import Debug.Trace qualified as IO (traceEventIO, traceMarkerIO)
+import Debug.Trace qualified as IO
 
 class Monad m => MonadEventlog m where
 
@@ -17,13 +17,18 @@
   -- profiling tools to help you keep clear which marker is which.
   traceMarkerIO :: String -> m ()
 
+  -- | Immediately flush the event log, if enabled.
+  --
+  flushEventLog :: m ()
+
 --
 -- Instances for IO
 --
 
 instance MonadEventlog IO where
-  traceEventIO = IO.traceEventIO
+  traceEventIO  = IO.traceEventIO
   traceMarkerIO = IO.traceMarkerIO
+  flushEventLog = IO.flushEventLog
 
 --
 -- Instance for ReaderT
@@ -32,3 +37,4 @@
 instance MonadEventlog m => MonadEventlog (ReaderT r m) where
   traceEventIO  = lift . traceEventIO
   traceMarkerIO = lift . traceMarkerIO
+  flushEventLog = lift   flushEventLog
diff --git a/io-classes/Control/Monad/Class/MonadThrow.hs b/io-classes/Control/Monad/Class/MonadThrow.hs
--- a/io-classes/Control/Monad/Class/MonadThrow.hs
+++ b/io-classes/Control/Monad/Class/MonadThrow.hs
@@ -210,7 +210,7 @@
 
 -- | Monads which can 'evaluate'.
 --
-class MonadEvaluate m where
+class Monad m => MonadEvaluate m where
     evaluate :: a -> m a
 
 --
diff --git a/mtl/Control/Monad/Class/MonadEventlog/Trans.hs b/mtl/Control/Monad/Class/MonadEventlog/Trans.hs
--- a/mtl/Control/Monad/Class/MonadEventlog/Trans.hs
+++ b/mtl/Control/Monad/Class/MonadEventlog/Trans.hs
@@ -18,39 +18,46 @@
 instance MonadEventlog m => MonadEventlog (ContT r m) where
   traceEventIO  = lift . traceEventIO
   traceMarkerIO = lift . traceMarkerIO
+  flushEventLog = lift   flushEventLog
 
 -- | @since 0.1.0.0
 instance MonadEventlog m => MonadEventlog (ExceptT e m) where
   traceEventIO  = lift . traceEventIO
   traceMarkerIO = lift . traceMarkerIO
+  flushEventLog = lift   flushEventLog
 
 -- | @since 0.1.0.0
 instance (Monoid w, MonadEventlog m) => MonadEventlog (Lazy.RWST r w s m) where
   traceEventIO  = lift . traceEventIO
   traceMarkerIO = lift . traceMarkerIO
+  flushEventLog = lift   flushEventLog
 
 -- | @since 0.1.0.0
 instance (Monoid w, MonadEventlog m) => MonadEventlog (Strict.RWST r w s m) where
   traceEventIO  = lift . traceEventIO
   traceMarkerIO = lift . traceMarkerIO
+  flushEventLog = lift   flushEventLog
 
 -- | @since 0.1.0.0
 instance MonadEventlog m => MonadEventlog (Lazy.StateT s m) where
   traceEventIO  = lift . traceEventIO
   traceMarkerIO = lift . traceMarkerIO
+  flushEventLog = lift   flushEventLog
 
 -- | @since 0.1.0.0
 instance MonadEventlog m => MonadEventlog (Strict.StateT s m) where
   traceEventIO  = lift . traceEventIO
   traceMarkerIO = lift . traceMarkerIO
+  flushEventLog = lift   flushEventLog
 
 -- | @since 0.1.0.0
 instance (Monoid w, MonadEventlog m) => MonadEventlog (Lazy.WriterT w m) where
   traceEventIO  = lift . traceEventIO
   traceMarkerIO = lift . traceMarkerIO
+  flushEventLog = lift   flushEventLog
 
 -- | @since 0.1.0.0
 instance (Monoid w, MonadEventlog m) => MonadEventlog (Strict.WriterT w m) where
   traceEventIO  = lift . traceEventIO
   traceMarkerIO = lift . traceMarkerIO
-
+  flushEventLog = lift   flushEventLog