diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,13 +1,17 @@
+# log-base-0.7.3.0 (2017-10-10)
+* `BasicStdOutLogger` now flushes stdout on each write. `BulkStdOutLogger`
+  now flushes stdout on each bulk write ([#38](https://github.com/scrive/log/issues/38)).
+
 # log-base-0.7.2.0 (2017-08-10)
-* Add 'MFunctor LogT' instance
+* Add 'MFunctor LogT' instance ([#35](https://github.com/scrive/log/issues/35) ).
 
 # log-base-0.7.1.1 (2017-06-19)
 * mkBulkLogger now uses a bounded queue to interact with the logger thread.
 
 # log-base-0.7.1 (2017-03-16)
-* Added a few MTL class instances (#28).
+* Added a few MTL class instances ([#28](https://github.com/scrive/log/issues/28)).
 
 # log-base-0.7 (2016-11-25)
 * Initial release (split from the log package).
-* Improved documentation (#22).
-* Implement 'toEncoding' directly in 'ToJSON' instances (#21).
+* Improved documentation ([#22](https://github.com/scrive/log/issues/22)).
+* Implement 'toEncoding' directly in 'ToJSON' instances ([#21](https://github.com/scrive/log/issues/21)).
diff --git a/log-base.cabal b/log-base.cabal
--- a/log-base.cabal
+++ b/log-base.cabal
@@ -1,5 +1,5 @@
 name:                log-base
-version:             0.7.2.0
+version:             0.7.3.0
 synopsis:            Structured logging solution (base package)
 
 description:         A library that provides a way to record structured log
@@ -37,7 +37,7 @@
                        Log.Internal.Logger,
                        Log.Logger,
                        Log.Monad
-  build-depends:       base <5,
+  build-depends:       base >= 4.8 && <5,
                        aeson >=0.11.0.0,
                        aeson-pretty >=0.8.2,
                        bytestring,
diff --git a/src/Log/Backend/StandardOutput.hs b/src/Log/Backend/StandardOutput.hs
--- a/src/Log/Backend/StandardOutput.hs
+++ b/src/Log/Backend/StandardOutput.hs
@@ -22,10 +22,14 @@
 
 {-# DEPRECATED simpleStdoutLogger "Use 'withSimpleStdOutLogger'" #-}
 
--- | Simple, synchronous logger that prints messages to standard output.
+-- | Simple, synchronous logger that prints messages to standard
+-- output. Flushes 'stdout' on each call to 'loggerWriteMessage'. Use
+-- 'Log.Backend.StandardOutput.Bulk.withBulkStdOutLogger' if you want
+-- buffering.
 simpleStdoutLogger :: Logger
 simpleStdoutLogger = Logger {
-    loggerWriteMessage = T.putStrLn . showLogMessage Nothing
+    loggerWriteMessage = \msg -> (T.putStrLn . showLogMessage Nothing $ msg)
+                                 >> hFlush stdout
   , loggerWaitForWrite = hFlush stdout
   , loggerShutdown     = return ()
   }
diff --git a/src/Log/Backend/StandardOutput/Bulk.hs b/src/Log/Backend/StandardOutput/Bulk.hs
--- a/src/Log/Backend/StandardOutput/Bulk.hs
+++ b/src/Log/Backend/StandardOutput/Bulk.hs
@@ -6,6 +6,7 @@
 
 import Prelude
 import qualified Data.Text.IO as T
+import System.IO (hFlush, stdout)
 
 import Log.Data
 import Log.Logger
@@ -13,7 +14,7 @@
 
 -- | Create a 'bulkStdoutLogger' for the duration of the given action,
 -- and shut it down afterwards, making sure that all buffered messages
--- are actually written to stdout.
+-- are actually written to stdout. Flushes 'stdout' on each bulk write.
 withBulkStdOutLogger :: (Logger -> IO r) -> IO r
 withBulkStdOutLogger act = do
   logger <- bulkStdoutLogger
@@ -28,5 +29,6 @@
 -- (see the note attached to 'mkBulkLogger').
 bulkStdoutLogger :: IO Logger
 bulkStdoutLogger = mkBulkLogger "stdout-bulk"
-                   (mapM_ $ T.putStrLn . showLogMessage Nothing)
-                   (return ())
+                   (\msgs -> mapM_ (T.putStrLn . showLogMessage Nothing) msgs
+                             >> hFlush stdout)
+                   (hFlush stdout)