diff --git a/CHANGES.md b/CHANGES.md
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,8 @@
+1.8.10.1
+======
+
+* Make `o-clock` non-optional dependency.
+
 1.8.10
 ======
 
diff --git a/log-warper.cabal b/log-warper.cabal
--- a/log-warper.cabal
+++ b/log-warper.cabal
@@ -1,5 +1,5 @@
 name:                log-warper
-version:             1.8.10
+version:             1.8.10.1
 synopsis:            Flexible, configurable, monadic and pretty logging
 homepage:            https://github.com/serokell/log-warper
 license:             MIT
@@ -59,6 +59,7 @@
                      , monad-loops          ^>= 0.4.3
                      , mmorph               ^>= 1.1
                      , mtl                  ^>= 2.2.1
+                     , o-clock              ^>= 0.1.1
                      , text                 ^>= 1.2.2.0
                      , time                 ^>= 1.8
                      , transformers         ^>= 0.5.2
@@ -67,8 +68,6 @@
                      , unordered-containers >= 0.2.7.1
                      , vector               ^>= 0.12
                      , yaml                 ^>= 0.8.20
-  if impl(ghc >= 8.2.2)
-     build-depends:   o-clock ^>= 0.1
 
   if !os(windows)
     build-depends:     unix
diff --git a/src/System/Wlog.hs b/src/System/Wlog.hs
--- a/src/System/Wlog.hs
+++ b/src/System/Wlog.hs
@@ -1,5 +1,3 @@
-{-# LANGUAGE CPP #-}
-
 -- |
 -- Module      : System.Wlog
 -- Copyright   : (c) Serokell, 2016
@@ -15,9 +13,7 @@
 
 module System.Wlog
        ( module System.Wlog.CanLog
-#if ( __GLASGOW_HASKELL__ >= 802 )
        , module System.Wlog.Concurrent
-#endif
        , module System.Wlog.Exception
        , module System.Wlog.FileUtils
        , module System.Wlog.HasLoggerName
@@ -34,9 +30,7 @@
        ) where
 
 import System.Wlog.CanLog
-#if ( __GLASGOW_HASKELL__ >= 802 )
 import System.Wlog.Concurrent
-#endif
 import System.Wlog.Exception
 import System.Wlog.FileUtils
 import System.Wlog.HasLoggerName