diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,10 @@
 
+5.28.1
+------
+
+Bug fixes:
+ * `installUnicodeWidthTable`: use `throwIO`, not `throw`
+
 5.28
 ----
 
diff --git a/src/Graphics/Vty/UnicodeWidthTable/Install.hs b/src/Graphics/Vty/UnicodeWidthTable/Install.hs
--- a/src/Graphics/Vty/UnicodeWidthTable/Install.hs
+++ b/src/Graphics/Vty/UnicodeWidthTable/Install.hs
@@ -9,7 +9,8 @@
 
 import Control.Monad (when, forM_)
 import qualified Control.Exception as E
-import Control.Concurrent.MVar (MVar, newMVar, takeMVar, putMVar)
+import GHC.Conc.Sync (withMVar)
+import Control.Concurrent.MVar (MVar, newMVar)
 import Data.Word (Word8, Word32)
 #if !(MIN_VERSION_base(4,11,0))
 import Data.Semigroup ((<>))
@@ -31,14 +32,7 @@
 isCustomTableReady = withInstallLock $ (== 1) <$> c_isCustomTableReady
 
 withInstallLock :: IO a -> IO a
-withInstallLock act =
-    E.bracket takeInstallLock (const releaseInstallLock) $ const act
-
-takeInstallLock :: IO ()
-takeInstallLock = takeMVar installLock
-
-releaseInstallLock :: IO ()
-releaseInstallLock = putMVar installLock ()
+withInstallLock act = withMVar installLock $ const act
 
 -- This is the size of the allocated custom character width table, in
 -- character slots. It's important that this be large enough to hold all
@@ -101,7 +95,7 @@
 installUnicodeWidthTable table = withInstallLock $ do
     initResult <- initCustomTable tableSize
     when (initResult /= 0) $
-        E.throw $ TableInitFailure initResult tableSize
+        E.throwIO $ TableInitFailure initResult tableSize
 
     forM_ (unicodeWidthTableRanges table) $ \r -> do
         result <- setCustomTableRange (rangeStart r)
@@ -110,11 +104,11 @@
 
         when (result /= 0) $ do
             deallocateCustomTable
-            E.throw $ TableRangeFailure result r
+            E.throwIO $ TableRangeFailure result r
 
     actResult <- activateCustomTable
     when (actResult /= 0) $
-        E.throw $ TableActivationFailure actResult
+        E.throwIO $ TableActivationFailure actResult
 
 ------------------------------------------------------------------------
 -- C imports
diff --git a/vty.cabal b/vty.cabal
--- a/vty.cabal
+++ b/vty.cabal
@@ -1,5 +1,5 @@
 name:                vty
-version:             5.28
+version:             5.28.1
 license:             BSD3
 license-file:        LICENSE
 author:              AUTHORS