diff --git a/CHANGES b/CHANGES
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,8 @@
+* 0.6.1
+  - Add contributions by Oleg Grenrus (@phadej)
+    - Make 'Semigroup' instances available on all `base` versions.
+    - Add 'Semigroup (Pair a b)' instance
+
 * 0.6.0
   - Add contribution by Bas van Dijk (@basvandijk)
     - Add 'Semigroup' instance for base-4.9.0.0
diff --git a/src/Data/Maybe/Strict.hs b/src/Data/Maybe/Strict.hs
--- a/src/Data/Maybe/Strict.hs
+++ b/src/Data/Maybe/Strict.hs
@@ -72,10 +72,8 @@
 #endif
 import           Test.QuickCheck     (Arbitrary (..))
 import           Data.Hashable       (Hashable(..))
-#if MIN_VERSION_base(4,9,0)
 import           Data.Semigroup      (Semigroup)
 import qualified Data.Semigroup      as Semigroup
-#endif
 
 
 -- utilities
@@ -100,19 +98,22 @@
 deriving instance Generic  (Maybe a)
 #endif
 
-#if MIN_VERSION_base(4,9,0)
 instance Semigroup a => Semigroup (Maybe a) where
   Nothing <> m       = m
   m       <> Nothing = m
   Just x1 <> Just x2 = Just (x1 Semigroup.<> x2)
-#endif
 
+#if MIN_VERSION_base(4,11,0)
+instance Semigroup a => Monoid (Maybe a) where
+  mempty = Nothing
+#else
 instance Monoid a => Monoid (Maybe a) where
   mempty = Nothing
 
   Nothing `mappend` m       = m
   m       `mappend` Nothing = m
   Just x1 `mappend` Just x2 = Just (x1 `mappend` x2)
+#endif
 
 -- foldable
 instance Foldable Maybe where
diff --git a/src/Data/Tuple/Strict.hs b/src/Data/Tuple/Strict.hs
--- a/src/Data/Tuple/Strict.hs
+++ b/src/Data/Tuple/Strict.hs
@@ -72,6 +72,7 @@
 #endif
 import           Test.QuickCheck     (Arbitrary (..))
 import           Data.Hashable       (Hashable(..))
+import           Data.Semigroup      (Semigroup (..))
 
 #if __HADDOCK__
 import Data.Tuple ()
@@ -110,6 +111,9 @@
 
 instance Traversable (Pair e) where
   traverse f (e :!: x) = (:!:) e <$> f x
+
+instance (Semigroup a, Semigroup b) => Semigroup (Pair a b) where
+  (x1 :!: y1) <> (x2 :!: y2) = (x1 <> x2) :!: (y1 <> y2)
 
 instance (Monoid a, Monoid b) => Monoid (Pair a b) where
   mempty                            = mempty :!: mempty
diff --git a/strict-base-types.cabal b/strict-base-types.cabal
--- a/strict-base-types.cabal
+++ b/strict-base-types.cabal
@@ -1,5 +1,5 @@
 Name:           strict-base-types
-Version:        0.6.0
+Version:        0.6.1
 Synopsis:       Strict variants of the types provided in base.
 Category:       Data
 Description:
@@ -100,7 +100,14 @@
 Homepage:       https://github.com/meiersi/strict-base-types
 Cabal-Version: >= 1.6
 Build-type:     Simple
-Tested-with:    GHC==7.4.2, GHC==7.6.3, GHC==7.8.4, GHC==7.10.2
+Tested-with:
+  GHC==7.4.2,
+  GHC==7.6.3,
+  GHC==7.8.4,
+  GHC==7.10.3,
+  GHC==8.0.2,
+  GHC==8.2.2,
+  GHC==8.4.1
 
 extra-source-files:
   CHANGES
@@ -111,6 +118,8 @@
 
 library
   ghc-options:    -Wall -fwarn-incomplete-uni-patterns
+  if impl(ghc >= 8.0)
+    ghc-options: -Wcompat -Wnoncanonical-monad-instances -Wnoncanonical-monadfail-instances
   build-depends:
       base       >= 4.5 && < 5
     , lens       >= 3.9
@@ -119,9 +128,13 @@
     , binary     >= 0.5
     , deepseq    >= 1.3
     , hashable   >= 1.1.1.0
-    , strict     == 0.3.*
+    , strict     >= 0.3.2 && <0.4
     , bifunctors >= 3.0
     , ghc-prim
+
+  if !impl(ghc >= 8.0)
+    build-depends: semigroups >= 0.18.3
+
   hs-source-dirs:    src
   exposed-modules:
       Data.Tuple.Strict