diff --git a/Changelog.md b/Changelog.md
--- a/Changelog.md
+++ b/Changelog.md
@@ -1,3 +1,11 @@
+### 1.2.13.1
+
+- Module *NgxExport.Tools.Aggregate*.
+  + Remove unnecessary wrapping of the reported value in *Maybe*.
+  + Drop dependency on modules from package *text*.
+- Drop support for GHC versions older than *9.6* due to the updated constraints
+  in revision *3* of package *base64-1.0* on Hackage.
+
 ### 1.2.13
 
 - Module *NgxExport.Tools.Prometheus*.
diff --git a/NgxExport/Tools/Aggregate.hs b/NgxExport/Tools/Aggregate.hs
--- a/NgxExport/Tools/Aggregate.hs
+++ b/NgxExport/Tools/Aggregate.hs
@@ -65,8 +65,6 @@
 import           Text.Read
 
 #ifdef SNAP_AGGREGATE_SERVER
-import qualified Data.Text as T
-import qualified Data.Text.Encoding as T
 import           Control.Monad.IO.Class
 import           Control.Exception.Enclosed (handleAny)
 import           Snap.Http.Server
@@ -77,7 +75,7 @@
 type AggregateValue a = (UTCTime, Map Int32 (UTCTime, Maybe a))
 type Aggregate a = IORef (AggregateValue a)
 
-type ReportValue a = Maybe (Int32, Maybe a)
+type ReportValue a = (Int32, Maybe a)
 
 -- $aggregateServiceExporter
 --
@@ -310,9 +308,8 @@
 toNominalDiffTime =
     secondsToNominalDiffTime . asIntegerPart . fromIntegral . toSec
 
-updateAggregate :: Aggregate a -> ReportValue a -> NominalDiffTime -> IO ()
-updateAggregate a s int = do
-    let (pid, v) = fromJust s
+updateAggregate :: Aggregate a -> NominalDiffTime -> ReportValue a -> IO ()
+updateAggregate a int (!pid, !v) = do
     !t <- getCurrentTime
     atomicModifyIORef' a $
         \(t', v') ->
@@ -337,11 +334,10 @@
 receiveAggregate :: FromJSON a =>
     Aggregate a -> LazyByteString -> ByteString -> IO LazyByteString
 receiveAggregate a v sint = do
-    let !s = decode' v
-        !int = toNominalDiffTime $
+    let !int = toNominalDiffTime $
             fromMaybe (Min 5) $ readMaybe $ C8.unpack sint
-    when (isNothing s) $ throwUserError "Unreadable aggregate!"
-    updateAggregate a (fromJust s) int
+    maybe (throwUserError "Unreadable aggregate!")
+        (updateAggregate a int) $ decode' v
     return "done"
 
 sendAggregate :: ToJSON a =>
@@ -405,9 +401,9 @@
 receiveAggregateSnap :: FromJSON a => Aggregate a -> NominalDiffTime -> Snap ()
 receiveAggregateSnap a int =
     handleAggregateExceptions "Exception while receiving aggregate" $ do
-        !s <- decode' <$> readRequestBody 65536
-        when (isNothing s) $ liftIO $ throwUserError "Unreadable aggregate!"
-        liftIO $ updateAggregate a (fromJust s) int
+        v <- readRequestBody 65536
+        maybe (liftIO $ throwUserError "Unreadable aggregate!")
+            (liftIO . updateAggregate a int) $ decode' v
         finishWith emptyResponse
 
 sendAggregateSnap :: ToJSON a => Aggregate a -> Snap ()
@@ -417,12 +413,11 @@
         modifyResponse $ setContentType "application/json"
         writeLBS $ encode s
 
-handleAggregateExceptions :: String -> Snap () -> Snap ()
-handleAggregateExceptions cmsg = handleAny $ \e ->
-    writeErrorResponse 500 $ show (e :: SomeException)
+handleAggregateExceptions :: ByteString -> Snap () -> Snap ()
+handleAggregateExceptions cmsg = handleAny $ writeErrorResponse 500 . show
     where writeErrorResponse c msg = do
-              modifyResponse $ setResponseStatus c $ T.encodeUtf8 $ T.pack cmsg
-              writeBS $ T.encodeUtf8 $ T.pack msg
+              modifyResponse $ setResponseStatus c cmsg
+              writeBS $ C8.pack msg
 
 #endif
 
diff --git a/ngx-export-tools-extra.cabal b/ngx-export-tools-extra.cabal
--- a/ngx-export-tools-extra.cabal
+++ b/ngx-export-tools-extra.cabal
@@ -1,5 +1,5 @@
 name:                       ngx-export-tools-extra
-version:                    1.2.13
+version:                    1.2.13.1
 synopsis:                   More extra tools for Nginx Haskell module
 description:                More extra tools for
         <https://github.com/lyokha/nginx-haskell-module Nginx Haskell module>.
@@ -30,7 +30,7 @@
 
 library
   default-language:         Haskell2010
-  build-depends:            base >= 4.8 && < 5
+  build-depends:            base >= 4.18 && < 5
                           , template-haskell >= 2.11.0.0
                           , bytestring >= 0.11.2.0
                           , base64 >= 1.0