diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,8 +1,18 @@
+# Version 0.11.0.0 (2023-08-29)
+
+- Add support for GHC 9.8.
+
+- Re-export functionality relating to GHC's constraint solving `TcS` monad,
+  such as `{get,set}InertSet`, `{get,set}TcEvBindsMap`.
+
+- Re-export `readTcRef` and `writeTcRef`.
+
 # Version 0.10.0.0 (2023-02-28)
 
 - Introduce `resolveImport`, and make `PkgQual` opaque.
+
 - Rename `tcRewriterWanteds` to `tcRewriterNewWanteds`
-  (bringing it in line with nomenclature in ghc 9.4).
+  (bringing it in line with nomenclature in GHC 9.4).
 
 # Version 0.9.0.0 (2023-01-24)
 
diff --git a/ghc-tcplugin-api.cabal b/ghc-tcplugin-api.cabal
--- a/ghc-tcplugin-api.cabal
+++ b/ghc-tcplugin-api.cabal
@@ -1,6 +1,6 @@
 cabal-version:  3.0
 name:           ghc-tcplugin-api
-version:        0.10.0.0
+version:        0.11.0.0
 synopsis:       An API for type-checker plugins.
 license:        BSD-3-Clause
 build-type:     Simple
@@ -33,11 +33,11 @@
 
   build-depends:
     base
-      >= 4.13.0 && < 4.19,
+      >= 4.13.0 && < 4.20,
     containers
       >= 0.6    && < 0.7,
     ghc
-      >= 8.8    && < 9.7,
+      >= 8.8    && < 9.9,
     transformers
       >= 0.5    && < 0.7,
 
diff --git a/src/GHC/TcPlugin/API.hs b/src/GHC/TcPlugin/API.hs
--- a/src/GHC/TcPlugin/API.hs
+++ b/src/GHC/TcPlugin/API.hs
@@ -241,6 +241,7 @@
   , isSkolemTyVar
   , isMetaTyVar, isFilledMetaTyVar_maybe
   , writeMetaTyVar
+  , readTcRef, writeTcRef
 
     -- | == Some further functions for inspecting constraints
   , eqType
@@ -428,6 +429,11 @@
     -- * The type-checking environment
   , getEnvs
 
+    -- * Interacting with GHC's constraint solver
+  , TcS
+  , InertSet, getInertSet, setInertSet
+  , getTcEvBindsMap, setTcEvBindsMap
+
     -- * Built-in types
 
     -- | This module also re-exports the built-in types that GHC already knows about.
@@ -579,6 +585,22 @@
   ( FastString, fsLit, unpackFS )
 import qualified GHC.Tc.Plugin
   as GHC
+#if MIN_VERSION_ghc(9,4,0)
+import GHC.Tc.Solver.InertSet
+  ( InertSet )
+#endif
+import GHC.Tc.Solver.Monad
+  ( TcS
+#if !MIN_VERSION_ghc(9,4,0)
+  , InertSet
+#endif
+#if MIN_VERSION_ghc(9,8,0)
+  , getInertSet, updInertSet
+#else
+  , getTcSInerts, setTcSInerts
+#endif
+  , getTcEvBindsMap, setTcEvBindsMap
+  )
 import GHC.Tc.Types
   ( TcTyThing(..), TcGblEnv(..), TcLclEnv(..)
 #if HAS_REWRITING
@@ -601,7 +623,7 @@
 import GHC.Tc.Types.Origin
   ( CtOrigin(..) )
 import GHC.Tc.Utils.Monad
-  ( newName )
+  ( newName, readTcRef, writeTcRef )
 import qualified GHC.Tc.Utils.Monad
   as GHC
     ( traceTc, setCtLocM )
@@ -1064,3 +1086,20 @@
 
 #endif
 #endif
+
+--------------------------------------------------------------------------------
+
+#if MIN_VERSION_ghc(9,8,0)
+setInertSet :: InertSet -> TcS ()
+setInertSet inerts = updInertSet ( const inerts )
+  -- workaround for setInertSet not being exported
+
+#elif !MIN_VERSION_ghc(9,8,0)
+getInertSet :: TcS InertSet
+getInertSet = getTcSInerts
+
+setInertSet :: InertSet -> TcS ()
+setInertSet = setTcSInerts
+#endif
+
+--------------------------------------------------------------------------------
diff --git a/src/GHC/TcPlugin/API/Names.hs b/src/GHC/TcPlugin/API/Names.hs
--- a/src/GHC/TcPlugin/API/Names.hs
+++ b/src/GHC/TcPlugin/API/Names.hs
@@ -130,6 +130,10 @@
   ( MonadTrans(lift) )
 
 -- ghc
+#if MIN_VERSION_ghc(9,8,0)
+import GHC.Iface.Errors.Ppr
+  ( missingInterfaceErrorDiagnostic )
+#endif
 #if MIN_VERSION_ghc(9,3,0)
 import GHC.Iface.Errors
   ( cannotFindModule )
@@ -141,8 +145,6 @@
   ( hsc_dflags )
 import GHC.Driver.Finder
   ( cannotFindModule )
-import GHC.Driver.Session
-  ( DynFlags )
 #endif
 #if MIN_VERSION_ghc(9,5,0)
 import Language.Haskell.Syntax.Module.Name
@@ -155,6 +157,10 @@
   ( pgmErrorDoc )
 import GHC.Tc.Plugin
   ( getTopEnv )
+#if MIN_VERSION_ghc(9,8,0)
+import GHC.Types.Error
+  ( HasDefaultDiagnosticOpts(defaultOpts) )
+#endif
 
 -- ghc-tcplugin-api
 import GHC.TcPlugin.API
@@ -402,12 +408,14 @@
           hsc_env <- lift . liftTcPluginM $ getTopEnv
           let
             err_doc :: SDoc
+            err_doc =
+#if MIN_VERSION_ghc(9,8,0)
+              missingInterfaceErrorDiagnostic defaultOpts $
+#endif
 #if MIN_VERSION_ghc(9,2,0)
-            err_doc = cannotFindModule hsc_env mod_name other
+              cannotFindModule hsc_env mod_name other
 #else
-            err_doc = cannotFindModule dflags  mod_name other
-            dflags :: DynFlags
-            dflags = hsc_dflags hsc_env
+              cannotFindModule (hsc_dflags hsc_env) mod_name other
 #endif
           pgmErrorDoc
             (    "GHC.TcPlugin.API: could not find module "