diff --git a/compiler/cbits/genSym.c b/compiler/cbits/genSym.c
--- a/compiler/cbits/genSym.c
+++ b/compiler/cbits/genSym.c
@@ -9,7 +9,9 @@
 //
 // The CPP is thus about the RTS version GHC is linked against, and not the
 // version of the GHC being built.
-#if !MIN_VERSION_GLASGOW_HASKELL(9,9,0,0)
+#if !MIN_VERSION_GLASGOW_HASKELL(9,6,7,0)
+HsWord64 ghc_unique_counter64 = 0;
+#elif MIN_VERSION_GLASGOW_HASKELL(9,8,0,0) && !MIN_VERSION_GLASGOW_HASKELL(9,8,4,0)
 HsWord64 ghc_unique_counter64 = 0;
 #endif
 #if !MIN_VERSION_GLASGOW_HASKELL(9,3,0,0)
diff --git a/ghc-lib-parser.cabal b/ghc-lib-parser.cabal
--- a/ghc-lib-parser.cabal
+++ b/ghc-lib-parser.cabal
@@ -1,7 +1,7 @@
 cabal-version: 3.0
 build-type: Simple
 name: ghc-lib-parser
-version: 9.12.2.20250320
+version: 9.12.2.20250421
 license: BSD-3-Clause
 license-file: LICENSE
 category: Development
diff --git a/ghc-lib/stage0/compiler/build/GHC/Settings/Config.hs b/ghc-lib/stage0/compiler/build/GHC/Settings/Config.hs
--- a/ghc-lib/stage0/compiler/build/GHC/Settings/Config.hs
+++ b/ghc-lib/stage0/compiler/build/GHC/Settings/Config.hs
@@ -22,7 +22,7 @@
 cProjectName          = "The Glorious Glasgow Haskell Compilation System"
 
 cBooterVersion        :: String
-cBooterVersion        = "9.12.2"
+cBooterVersion        = "9.12.1"
 
 cStage                :: String
 cStage                = show (1 :: Int)