diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,9 @@
 # Revision history for ordered-containers
 
+## 0.2.1 -- 2019-03-25
+
+* Compatibility fixes from Ryan Scott (thanks!)
+
 ## 0.2 -- 2019-03-24
 
 * Support many more operations:
diff --git a/Data/Map/Ordered.hs b/Data/Map/Ordered.hs
--- a/Data/Map/Ordered.hs
+++ b/Data/Map/Ordered.hs
@@ -41,10 +41,14 @@
 import Data.Function (on)
 import Data.Map (Map)
 import Data.Map.Util
-import Data.Monoid
+import Data.Monoid (Monoid(..))
 #if MIN_VERSION_base(4,9,0)
-import Data.Semigroup
+import Data.Semigroup (Semigroup(..))
 #endif
+#if !(MIN_VERSION_base(4,8,0))
+import Control.Applicative ((<$>))
+import Data.Traversable
+#endif
 import Prelude hiding (filter, lookup, null)
 import qualified Data.Map as M
 
@@ -67,7 +71,8 @@
 		1 -> k (z fromList)
 		_ -> error "gunfold"
 	dataTypeOf _   = oMapDataType
-	dataCast2      = gcast2
+	-- dataCast2 /must/ be eta-expanded in order to build on GHC 7.8.
+	dataCast2 f    = gcast2 f
 
 fromListConstr :: Constr
 fromListConstr = mkConstr oMapDataType "fromList" [] Prefix
diff --git a/Data/Set/Ordered.hs b/Data/Set/Ordered.hs
--- a/Data/Set/Ordered.hs
+++ b/Data/Set/Ordered.hs
@@ -36,9 +36,9 @@
 import Data.Function (on)
 import Data.Map (Map)
 import Data.Map.Util
-import Data.Monoid
+import Data.Monoid (Monoid(..))
 #if MIN_VERSION_base(4,9,0)
-import Data.Semigroup
+import Data.Semigroup (Semigroup(..))
 #endif
 import Data.Set (Set) -- so the haddocks link to the right place
 import Prelude hiding (filter, foldr, lookup, null)
@@ -63,7 +63,8 @@
 		1 -> k (z fromList)
 		_ -> error "gunfold"
 	dataTypeOf _   = oSetDataType
-	dataCast1      = gcast1
+	-- dataCast1 /must/ be eta-expanded in order to build on GHC 7.8.
+	dataCast1 f    = gcast1 f
 
 fromListConstr :: Constr
 fromListConstr = mkConstr oSetDataType "fromList" [] Prefix
diff --git a/ordered-containers.cabal b/ordered-containers.cabal
--- a/ordered-containers.cabal
+++ b/ordered-containers.cabal
@@ -1,5 +1,5 @@
 name:                ordered-containers
-version:             0.2
+version:             0.2.1
 synopsis:            Set- and Map-like types that remember the order elements were inserted
 license:             BSD3
 license-file:        LICENSE