diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,9 @@
 # Changelog for rio
 
+## 0.1.15.0
+
+* Include source in log messages
+
 ## 0.1.14.1
 
 * Support `unliftio-core` 0.2
diff --git a/rio.cabal b/rio.cabal
--- a/rio.cabal
+++ b/rio.cabal
@@ -4,10 +4,10 @@
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 6b5196ca703656226be396b57dc1cad657e697252fabe2a5da4c27bb45262263
+-- hash: 88c70b06dfc2b555bc230e489348124cfcbdc0bdbf0ef59810cae48053937a10
 
 name:           rio
-version:        0.1.14.1
+version:        0.1.15.0
 synopsis:       A standard library for Haskell
 description:    See README and Haddocks at <https://www.stackage.org/package/rio>
 category:       Control
diff --git a/src/RIO/Prelude/Logger.hs b/src/RIO/Prelude/Logger.hs
--- a/src/RIO/Prelude/Logger.hs
+++ b/src/RIO/Prelude/Logger.hs
@@ -35,6 +35,8 @@
   , logSticky
   , logStickyDone
     -- *** With source
+    --
+    -- $withSource
   , logDebugS
   , logInfoS
   , logWarnS
@@ -204,6 +206,17 @@
   -> m ()
 logOther = logGeneric "" . LevelOther
 
+-- $withSource
+--
+-- There is a set of logging functions that take an extra 'LogSource'
+-- argument to provide context, typically detailing what part of an
+-- application the message comes from.
+--
+-- For example, in verbose mode, @infoLogS "database" "connected"@ will
+-- result in
+--
+-- > [info] (database) connected
+
 -- | Log a debug level message with the given source.
 --
 -- @since 0.0.0.0
@@ -530,7 +543,7 @@
 setLogFormat f options = options { logFormat = f }
 
 simpleLogFunc :: LogOptions -> CallStack -> LogSource -> LogLevel -> Utf8Builder -> IO ()
-simpleLogFunc lo cs _src level msg = do
+simpleLogFunc lo cs src level msg = do
     logLevel   <- logMinLevel lo
     logVerbose <- logVerboseFormat lo
 
@@ -540,6 +553,7 @@
         timestamp <>
         getLevel logVerbose <>
         ansi reset <>
+        getSource <>
         logFormat lo msg <>
         getLoc <>
         ansi reset <>
@@ -581,6 +595,11 @@
              display name <>
              "] "
      | otherwise = mempty
+
+   getSource :: Utf8Builder
+   getSource = case src of
+     "" -> ""
+     _  -> "(" <> display src <> ") "
 
    getLoc :: Utf8Builder
    getLoc
diff --git a/test/RIO/LoggerSpec.hs b/test/RIO/LoggerSpec.hs
--- a/test/RIO/LoggerSpec.hs
+++ b/test/RIO/LoggerSpec.hs
@@ -74,3 +74,15 @@
       logInfo "should be formatted"
     builder <- readIORef ref
     toLazyByteString builder `shouldBe` "[context] should be formatted\n"
+  it "noSource" $ do
+    (ref, options) <- logOptionsMemory
+    withLogFunc options $ \lf -> runRIO lf $ do
+      logInfoS "tests" "should appear"
+    builder <- readIORef ref
+    toLazyByteString builder `shouldBe` "(tests) should appear\n"
+  it "noSource verbose" $ do
+    (ref, options) <- logOptionsMemory
+    withLogFunc (options & setLogVerboseFormat True) $ \lf -> runRIO lf $ do
+      logInfoS "tests" "should appear"
+    builder <- readIORef ref
+    toLazyByteString builder `shouldBe` "[info] (tests) should appear\n"