diff --git a/cabal.project b/cabal.project
index f950bdb7..c8c82adc 100644
--- a/cabal.project
+++ b/cabal.project
@@ -1,4 +1,4 @@
-index-state: hackage.haskell.org 2025-01-14T02:09:49Z
+index-state: hackage.haskell.org 2025-01-15T06:45:23Z
 
 packages: ./io-sim
           ./io-classes
@@ -12,7 +12,7 @@ package io-classes
 package strict-stm
   flags: +asserts
 
-if impl (ghc >= 9.10.2)
+if impl (ghc >= 9.12)
   allow-newer:
     -- Stuck on `cabal-3.14` issues and recalcitrant maintainers
     -- https://github.com/haskell/aeson/issues/1124
diff --git a/io-classes/CHANGELOG.md b/io-classes/CHANGELOG.md
index ea6e6c03..6d0a6be4 100644
--- a/io-classes/CHANGELOG.md
+++ b/io-classes/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Revsion history of io-classes
 
+### 1.8.0.1
+
+* Added support for `ghc-9.2`.
+
 ### 1.8.0.0
 
 ### Breaking changes
diff --git a/io-classes/io-classes.cabal b/io-classes/io-classes.cabal
index 0eaa21e7..14516eab 100644
--- a/io-classes/io-classes.cabal
+++ b/io-classes/io-classes.cabal
@@ -1,6 +1,6 @@
 cabal-version:       3.4
 name:                io-classes
-version:             1.8.0.0
+version:             1.8.0.1
 synopsis:            Type classes for concurrency with STM, ST and timing
 description:
   IO Monad class hierarchy compatible with:
@@ -89,7 +89,7 @@ library
                        Control.Monad.Class.MonadTest
   default-language:    GHC2021
   default-extensions:  LambdaCase
-  build-depends:       base  >=4.9 && <4.22,
+  build-depends:       base  >=4.16 && <4.22,
                        array,
                        async >=2.1 && <2.3,
                        bytestring,
@@ -118,6 +118,8 @@ library strict-stm
   reexported-modules:  Control.Concurrent.Class.MonadSTM.TSem as Control.Concurrent.Class.MonadSTM.Strict.TSem
   default-language:    GHC2021
   default-extensions:  LambdaCase
+  if impl(ghc < 9.4)
+    default-extensions: GADTs
   build-depends:       base,
                        array,
 
@@ -134,6 +136,8 @@ library strict-mvar
   exposed-modules:     Control.Concurrent.Class.MonadMVar.Strict
   default-language:    GHC2021
   default-extensions:  LambdaCase
+  if impl(ghc < 9.4)
+    default-extensions: GADTs
   build-depends:       base,
                        io-classes:io-classes,
 
diff --git a/io-sim/io-sim.cabal b/io-sim/io-sim.cabal
index dcfbe198..92413a9e 100644
--- a/io-sim/io-sim.cabal
+++ b/io-sim/io-sim.cabal
@@ -62,7 +62,7 @@ library
                        Data.Deque.Strict
   default-language:    GHC2021
   default-extensions:  LambdaCase
-  build-depends:       base              >=4.9 && <4.22,
+  build-depends:       base              >=4.16 && <4.22,
                        io-classes:{io-classes,strict-stm,si-timers}
                                         ^>=1.6 || ^>= 1.7 || ^>= 1.8,
                        exceptions        >=0.10,