diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,10 @@
 
+Version 0.3
+-----
+
+* Using the mwc-random package for generating random numbers by default.
+
+
 Version 0.2
 -----
 
diff --git a/Simulation/Aivika/Branch/Generator.hs b/Simulation/Aivika/Branch/Generator.hs
--- a/Simulation/Aivika/Branch/Generator.hs
+++ b/Simulation/Aivika/Branch/Generator.hs
@@ -17,6 +17,7 @@
 import Control.Monad
 import Control.Monad.Trans
 
+import qualified System.Random.MWC as MWC
 import System.Random
 
 import Data.IORef
@@ -67,7 +68,10 @@
   newGenerator tp =
     case tp of
       SimpleGenerator ->
-        liftIO newStdGen >>= newRandomGenerator
+        do let g = MWC.uniform <$>
+                   MWC.withSystemRandom (return :: MWC.GenIO -> IO MWC.GenIO)
+           g' <- liftIO g
+           newRandomGenerator01 (liftIO g')
       SimpleGeneratorWithSeed x ->
         error "Unsupported generator type SimpleGeneratorWithSeed: newGenerator"
       CustomGenerator g ->
diff --git a/aivika-branches.cabal b/aivika-branches.cabal
--- a/aivika-branches.cabal
+++ b/aivika-branches.cabal
@@ -1,5 +1,5 @@
 name:            aivika-branches
-version:         0.2
+version:         0.3
 synopsis:        Nested discrete event simulation module for the Aivika library
 description:
     This package extends the aivika-transformers [1] library and allows creating branches to run
@@ -50,8 +50,9 @@
                      mtl >= 2.1.1,
                      containers >= 0.4.0.0,
                      random >= 1.0.0.3,
-                     aivika >= 5.1,
-                     aivika-transformers >= 5.1
+                     mwc-random >= 0.13.0.0,
+                     aivika >= 5.2,
+                     aivika-transformers >= 5.2
 
     extensions:      TypeFamilies,
                      MultiParamTypeClasses,