diff --git a/Simulation/Aivika/Experiment/Base/ExperimentWriter.hs b/Simulation/Aivika/Experiment/Base/ExperimentWriter.hs
--- a/Simulation/Aivika/Experiment/Base/ExperimentWriter.hs
+++ b/Simulation/Aivika/Experiment/Base/ExperimentWriter.hs
@@ -105,17 +105,13 @@
 
   {-# INLINE pure #-}
   pure a =
-    ExperimentWriter $ \r -> return a
+    ExperimentWriter $ \r -> pure a
 
   {-# INLINE (<*>) #-}
   (ExperimentWriter f) <*> (ExperimentWriter m) =
     ExperimentWriter $ \r -> f r <*> m r
 
 instance Monad ExperimentWriter where
-
-  {-# INLINE return #-}
-  return a =
-    ExperimentWriter $ \r -> return a
 
   {-# INLINE (>>=) #-}
   (ExperimentWriter m) >>= k =
diff --git a/Simulation/Aivika/Experiment/Base/HtmlWriter.hs b/Simulation/Aivika/Experiment/Base/HtmlWriter.hs
--- a/Simulation/Aivika/Experiment/Base/HtmlWriter.hs
+++ b/Simulation/Aivika/Experiment/Base/HtmlWriter.hs
@@ -55,8 +55,6 @@
 
 instance Monad HtmlWriter where
   
-  return a = HtmlWriter $ \f -> return (a, f)
-  
   (HtmlWriter m) >>= k = HtmlWriter $ \f ->
     do (a, f') <- m f
        let HtmlWriter m' = k a
@@ -74,7 +72,8 @@
 
 instance Applicative HtmlWriter where
 
-  pure = return
+  pure a = HtmlWriter $ \f -> pure (a, f)
+  
   (<*>) = ap
        
 -- | Write the HTML code.
diff --git a/aivika-experiment.cabal b/aivika-experiment.cabal
--- a/aivika-experiment.cabal
+++ b/aivika-experiment.cabal
@@ -1,5 +1,5 @@
 name:            aivika-experiment
-version:         5.3.3
+version:         5.4.0
 synopsis:        Simulation experiments for the Aivika library
 description:
     This package allows defining simulation experiments based on the aivika [1]
@@ -17,10 +17,10 @@
 category:        Simulation
 license:         BSD3
 license-file:    LICENSE
-copyright:       (c) 2012-2017. David Sorokin <david.sorokin@gmail.com>
+copyright:       (c) 2012-2023. David Sorokin <davsor@mail.ru>
 author:          David Sorokin
-maintainer:      David Sorokin <david.sorokin@gmail.com>
-homepage:        http://www.aivikasoft.com
+maintainer:      David Sorokin <davsor@mail.ru>
+homepage:        https://gitflic.ru/project/dsorokin/aivika-experiment
 cabal-version:   >= 1.10
 build-type:      Simple
 tested-with:     GHC == 7.10.1
@@ -62,8 +62,8 @@
                      split >= 0.2.2,
                      network-uri >= 2.6,
                      parallel-io >= 0.3.2.1,
-                     aivika >= 5.9.1,
-                     aivika-transformers >= 5.9.1
+                     aivika >= 6.0.0,
+                     aivika-transformers >= 6.0.0
 
     other-extensions:   MultiParamTypeClasses,
                         FlexibleContexts,
@@ -76,4 +76,4 @@
 source-repository head
 
     type:     git
-    location: https://github.com/dsorokin/aivika-experiment
+    location: https://gitflic.ru/project/dsorokin/aivika-experiment