diff --git a/AsyncRattus.cabal b/AsyncRattus.cabal
--- a/AsyncRattus.cabal
+++ b/AsyncRattus.cabal
@@ -1,6 +1,6 @@
 cabal-version:       1.18
 name:                AsyncRattus
-version:             0.1.0.1
+version:             0.1.0.2
 category:            FRP
 synopsis:            An asynchronous modal FRP language
 description:
@@ -160,6 +160,7 @@
   build-depends:       base >=4.16 && <5,
                        containers >= 0.6.5 && < 0.8,
                        ghc >= 9.2 && < 9.9,
+                       ghc-boot >= 9.2 && < 9.9,
                        hashtables >= 1.3.1 && < 1.4,
                        simple-affine-space >= 0.2.1 && < 0.3,
                        transformers >= 0.5.6 && < 0.7
@@ -182,6 +183,6 @@
   main-is:             WellTyped.hs
   hs-source-dirs:      test
   default-language:    Haskell2010
-  build-depends:       AsyncRattus, base, containers
+  build-depends:       AsyncRattus, base, containers, text
   ghc-options:         -fplugin=AsyncRattus.Plugin
 
diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # 0.1.0.1
 
+Make Integer and Text stable types
+
+# 0.1.0.1
+
 Compatibility with GHC 9.8
 
 # 0.1
diff --git a/docs/paper.pdf b/docs/paper.pdf
Binary files a/docs/paper.pdf and b/docs/paper.pdf differ
diff --git a/src/AsyncRattus/Plugin.hs b/src/AsyncRattus/Plugin.hs
--- a/src/AsyncRattus/Plugin.hs
+++ b/src/AsyncRattus/Plugin.hs
@@ -24,13 +24,8 @@
 import qualified Data.Set as Set
 import Data.Set (Set)
 
-#if __GLASGOW_HASKELL__ >= 900
 import GHC.Plugins
 import GHC.Tc.Types
-#else
-import GhcPlugins
-import TcRnTypes
-#endif
 
 -- | Use this to enable Asynchronous Rattus' plugin, either by supplying the option
 -- @-fplugin=AsyncRattus.Plugin@ directly to GHC, or by including the
@@ -153,14 +148,7 @@
 
 annotationsOn :: (Data a) => ModGuts -> CoreBndr -> CoreM [a]
 annotationsOn guts bndr = do
-#if __GLASGOW_HASKELL__ >= 900
   (_,anns)  <- getAnnotations deserializeWithData guts
   return $
     lookupWithDefaultUFM anns [] (varName bndr) ++
     getModuleAnnotations guts
-#else    
-  anns <- getAnnotations deserializeWithData guts
-  return $
-    lookupWithDefaultUFM anns [] (varUnique bndr) ++
-    getModuleAnnotations guts
-#endif
diff --git a/src/AsyncRattus/Plugin/CheckClockCompatibility.hs b/src/AsyncRattus/Plugin/CheckClockCompatibility.hs
--- a/src/AsyncRattus/Plugin/CheckClockCompatibility.hs
+++ b/src/AsyncRattus/Plugin/CheckClockCompatibility.hs
@@ -8,15 +8,8 @@
 module AsyncRattus.Plugin.CheckClockCompatibility
   (checkExpr, CheckExpr (..)) where
 
-#if __GLASGOW_HASKELL__ >= 902
 import GHC.Types.Tickish
-#endif
-
-#if __GLASGOW_HASKELL__ >= 900
 import GHC.Plugins
-#else
-import GhcPlugins
-#endif
 
 import AsyncRattus.Plugin.Utils
 import qualified AsyncRattus.Plugin.PrimExpr as Prim
diff --git a/src/AsyncRattus/Plugin/Dependency.hs b/src/AsyncRattus/Plugin/Dependency.hs
--- a/src/AsyncRattus/Plugin/Dependency.hs
+++ b/src/AsyncRattus/Plugin/Dependency.hs
@@ -11,35 +11,20 @@
 
 module AsyncRattus.Plugin.Dependency (dependency, HasBV (..),printBinds) where
 
-#if __GLASGOW_HASKELL__ >= 900
+
 import GHC.Plugins
 import GHC.Data.Bag
 import GHC.Hs.Type
-#else
-import GhcPlugins
-import Bag
-#if __GLASGOW_HASKELL__ >= 810
-import GHC.Hs.Types
-#else
-import HsTypes
-#endif
-#endif
 
-#if __GLASGOW_HASKELL__ >= 810
+
 import GHC.Hs.Extension
 import GHC.Hs.Expr
 import GHC.Hs.Pat
 import GHC.Hs.Binds
-#else 
-import HsExtension
-import HsExpr
-import HsPat
-import HsBinds
-#endif
 
 #if __GLASGOW_HASKELL__ >= 904
 import GHC.Parser.Annotation
-#elif __GLASGOW_HASKELL__ >= 902
+#else
 import Language.Haskell.Syntax.Extension
 import GHC.Parser.Annotation
 #endif
@@ -99,10 +84,7 @@
   getBV (PatBind {pat_lhs = pat}) = getBV pat
   getBV (VarBind {var_id = v}) = Set.singleton v
   getBV PatSynBind{} = Set.empty
-#if __GLASGOW_HASKELL__ < 900
-  getBV (XHsBindsLR e) = getBV e
-  getBV (AbsBinds {abs_exports = es}) = Set.fromList (map abe_poly es)
-#elif __GLASGOW_HASKELL__ < 904
+#if __GLASGOW_HASKELL__ < 904
   getBV (AbsBinds {abs_exports = es}) = Set.fromList (map abe_poly es)
 #else
   getBV (XHsBindsLR (AbsBinds {abs_exports = es})) = Set.fromList (map abe_poly es)
@@ -120,19 +102,15 @@
 getRecFieldRhs = hsRecFieldArg
 #endif
 
-#if __GLASGOW_HASKELL__ >= 902
 getConBV (PrefixCon _ ps) = getBV ps
-#else
-getConBV (PrefixCon ps) = getBV ps
-#endif
 getConBV (InfixCon p p') = getBV p `Set.union` getBV p'
 getConBV (RecCon (HsRecFields {rec_flds = fs})) = foldl run Set.empty fs
       where run s (L _ f) = getBV (getRecFieldRhs f) `Set.union` s
 
-#if __GLASGOW_HASKELL__ >= 900 && __GLASGOW_HASKELL__ < 904
+#if __GLASGOW_HASKELL__ < 904
 instance HasBV CoPat where
   getBV CoPat {co_pat_inner = p} = getBV p
-#elif __GLASGOW_HASKELL__ >= 904
+#else
 instance HasBV XXPatGhcTc where
   getBV CoPat {co_pat_inner = p} = getBV p
   getBV (ExpansionPat _ p) = getBV p
@@ -175,27 +153,11 @@
 #else
   getBV (ParPat _ p) = getBV p
 #endif
-#if __GLASGOW_HASKELL__ >= 900
   getBV (ConPat {pat_args = con}) = getConBV con
-#else
-  getBV (ConPatIn (L _ v) con) = Set.insert v (getConBV con)
-  getBV (ConPatOut {pat_args = con}) = getConBV con
-  getBV (CoPat _ _ p _) = getBV p
-#endif
-#if __GLASGOW_HASKELL__ >= 808
   getBV (SigPat _ p _) = getBV p
-#else
-  getBV (SigPat _ p)   = getBV p
-#endif
 
-#if __GLASGOW_HASKELL__ >= 904
-
-#elif __GLASGOW_HASKELL__ >= 810
-instance HasBV NoExtCon where
-#else
-instance HasBV NoExt where
-#endif
 #if __GLASGOW_HASKELL__ < 904
+instance HasBV NoExtCon where
   getBV _ = Set.empty
 #endif
 
@@ -221,44 +183,26 @@
 
 instance HasFV a => HasFV (MatchGroup GhcTc a) where
   getFV MG {mg_alts = alts} = getFV alts
-#if __GLASGOW_HASKELL__ < 900
-  getFV (XMatchGroup e) = getFV e
-#endif
   
 instance HasFV a => HasFV (Match GhcTc a) where
   getFV Match {m_grhss = rhss} = getFV rhss
-#if __GLASGOW_HASKELL__ < 900
-  getFV (XMatch e) = getFV e
-#endif
 
 instance HasFV (HsTupArg GhcTc) where
   getFV (Present _ e) = getFV e
   getFV Missing {} = Set.empty
-#if __GLASGOW_HASKELL__ < 900
-  getFV (XTupArg e) = getFV e
-#endif
 
 instance HasFV a => HasFV (GRHS GhcTc a) where
   getFV (GRHS _ g b) = getFV g `Set.union` getFV b
-#if __GLASGOW_HASKELL__ < 900
-  getFV (XGRHS e) = getFV e
-#endif
 
 instance HasFV a => HasFV (GRHSs GhcTc a) where
   getFV GRHSs {grhssGRHSs = rhs, grhssLocalBinds = lbs} =
     getFV rhs `Set.union` getFV lbs
-#if __GLASGOW_HASKELL__ < 900
-  getFV (XGRHSs e) = getFV e
-#endif
 
 
 instance HasFV (HsLocalBindsLR GhcTc GhcTc) where
   getFV (HsValBinds _ bs) = getFV bs
   getFV (HsIPBinds _ bs) = getFV bs
   getFV EmptyLocalBinds {} = Set.empty
-#if __GLASGOW_HASKELL__ < 900
-  getFV (XHsLocalBindsLR e) = getFV e
-#endif
   
 instance HasFV (HsValBindsLR GhcTc GhcTc) where
   getFV (ValBinds _ b _) = getFV b
@@ -277,70 +221,38 @@
 #else
   getFV (XHsBindsLR AbsBinds {abs_binds = bs}) = getFV bs
 #endif
-#if __GLASGOW_HASKELL__ < 900
-  getFV (XHsBindsLR e) = getFV e
-#endif
 
 instance HasFV (IPBind GhcTc) where
   getFV (IPBind _ _ e) = getFV e
-#if __GLASGOW_HASKELL__ < 900
-  getFV (XIPBind e) = getFV e
-#endif
 
 instance HasFV (HsIPBinds GhcTc) where
   getFV (IPBinds _ bs) = getFV bs
-#if __GLASGOW_HASKELL__ < 900
-  getFV (XHsIPBinds e) = getFV e
-#endif
   
 instance HasFV (ApplicativeArg GhcTc) where
-#if __GLASGOW_HASKELL__ >= 810
   getFV ApplicativeArgOne { arg_expr = e }     = getFV e
   getFV ApplicativeArgMany {app_stmts = es, final_expr = e} = getFV es `Set.union` getFV e
-#else
-  getFV (ApplicativeArgOne _ _ e _) = getFV e
-  getFV (ApplicativeArgMany _ es e _) = getFV es `Set.union` getFV e
-#endif
-#if __GLASGOW_HASKELL__ < 900
-  getFV (XApplicativeArg e) = getFV e
-#endif
 
 instance HasFV (ParStmtBlock GhcTc GhcTc) where
   getFV (ParStmtBlock _ es _ _) = getFV es
-#if __GLASGOW_HASKELL__ < 900
-  getFV (XParStmtBlock e) = getFV e
-#endif
   
 instance HasFV a => HasFV (StmtLR GhcTc GhcTc a) where
   getFV (LastStmt _ e _ _) = getFV e
-#if __GLASGOW_HASKELL__ >= 900
   getFV (BindStmt _ _ e) = getFV e
-#else
-  getFV (BindStmt _ _ e _ _) = getFV e
-#endif
   getFV (ApplicativeStmt _ args _) = foldMap (getFV . snd) args
   getFV (BodyStmt _ e _ _) = getFV e
   getFV (LetStmt _ bs) = getFV bs
   getFV (ParStmt _ stms e _) = getFV stms `Set.union` getFV e
   getFV TransStmt{} = Set.empty -- TODO
   getFV RecStmt{} = Set.empty -- TODO
-#if __GLASGOW_HASKELL__ < 900
-  getFV (XStmtLR e) = getFV e
-#endif
 
-#if __GLASGOW_HASKELL__ >= 902
+
 instance HasFV (HsRecFields GhcTc (GenLocated SrcSpanAnnA (HsExpr GhcTc))) where
-#else
-instance HasFV (HsRecordBinds GhcTc) where
-#endif
   getFV HsRecFields{rec_flds = fs} = getFV fs
 
 #if __GLASGOW_HASKELL__ >= 904
 instance HasFV (HsFieldBind o (GenLocated SrcSpanAnnA (HsExpr GhcTc))) where
-#elif __GLASGOW_HASKELL__ >= 902
-instance HasFV (HsRecField' o (GenLocated SrcSpanAnnA (HsExpr GhcTc))) where
 #else
-instance HasFV (HsRecField' o (LHsExpr GhcTc)) where
+instance HasFV (HsRecField' o (GenLocated SrcSpanAnnA (HsExpr GhcTc))) where
 #endif
   getFV rf  = getFV (getRecFieldRhs rf)
 
@@ -376,10 +288,8 @@
 #endif
 #if __GLASGOW_HASKELL__ >= 904
   getFV (HsCmdLamCase _ _ mg) = getFV mg
-#elif __GLASGOW_HASKELL__ >= 900
-  getFV (HsCmdLamCase _ mg) = getFV mg
 #else
-  getFV (HsCmdWrap _ _ cmd) = getFV cmd
+  getFV (HsCmdLamCase _ mg) = getFV mg
 #endif
   getFV (XCmd e) = getFV e
 
@@ -396,9 +306,6 @@
 
 instance HasFV (HsCmdTop GhcTc) where
   getFV (HsCmdTop _ cmd) = getFV cmd
-#if __GLASGOW_HASKELL__ < 900
-  getFV (XCmdTop e) = getFV e
-#endif
 
 instance HasFV (HsExpr GhcTc) where
   getFV (HsVar _ v) = getFV v
@@ -418,13 +325,9 @@
   getFV (HsCase _ e mg) = getFV e  `Set.union` getFV mg
   getFV (HsMultiIf _ es) = getFV es
   getFV (HsDo _ _ e) = getFV e
-#if __GLASGOW_HASKELL__ >= 902
   getFV HsProjection {} = Set.empty
   getFV HsGetField {gf_expr = e} = getFV e
   getFV (ExplicitList _ es) = getFV es
-#else
-  getFV (ExplicitList _ _ es) = getFV es
-#endif
   getFV (RecordUpd {rupd_expr = e, rupd_flds = fs}) = getFV e `Set.union` getFV fs
   getFV (RecordCon {rcon_flds = fs}) = getFV fs
   getFV (ArithSeq _ _ e) = getFV e
@@ -460,36 +363,14 @@
 #if __GLASGOW_HASKELL__ >= 906
   getFV (HsAppType _ e _ _) = getFV e
   getFV (ExprWithTySig _ e _) = getFV e  
-#elif __GLASGOW_HASKELL__ >= 808
+#else
   getFV (HsAppType _ e _) = getFV e
   getFV (ExprWithTySig _ e _) = getFV e  
-#else
-  getFV (ExprWithTySig _ e)   = getFV e
-  getFV (HsAppType _ e)   = getFV e
 #endif
-
-#if __GLASGOW_HASKELL__ >= 900
   getFV (HsIf _ e1 e2 e3) = getFV e1 `Set.union` getFV e2 `Set.union` getFV e3
   getFV (HsPragE _ _ e) = getFV e
-#else
-  getFV (HsIf _ _ e1 e2 e3) = getFV e1 `Set.union` getFV e2 `Set.union` getFV e3
-  getFV (HsSCC _ _ _ e) = getFV e
-  getFV (HsCoreAnn _ _ _ e) = getFV e
-  getFV (HsTickPragma _ _ _ _ e) = getFV e
-  getFV (HsWrap _ _ e) = getFV e
-#endif
 
-#if __GLASGOW_HASKELL__ < 810  
-  getFV (HsArrApp _ e1 e2 _ _) = getFV e1 `Set.union` getFV e2
-  getFV (HsArrForm _ e _ cmd) = getFV e `Set.union` getFV cmd
-  getFV EWildPat {} = Set.empty
-  getFV (EAsPat _ e1 e2) = getFV e1 `Set.union` getFV e2
-  getFV (EViewPat _ e1 e2) = getFV e1 `Set.union` getFV e2
-  getFV (ELazyPat _ e) = getFV e
-#endif
 
-
-#if __GLASGOW_HASKELL__ >= 900
 instance HasFV XXExprGhcTc where
   getFV (WrapExpr e) = getFV e
   getFV (ExpansionExpr (HsExpanded _e1 e2)) = getFV e2
@@ -502,10 +383,3 @@
 
 instance HasFV (e GhcTc) => HasFV (HsWrap e) where
   getFV (HsWrap _ e) = getFV e
-#elif __GLASGOW_HASKELL__ >= 810
-instance HasFV NoExtCon where
-  getFV _ = Set.empty
-#else
-instance HasFV NoExt where
-  getFV _ = Set.empty
-#endif
diff --git a/src/AsyncRattus/Plugin/PrimExpr.hs b/src/AsyncRattus/Plugin/PrimExpr.hs
--- a/src/AsyncRattus/Plugin/PrimExpr.hs
+++ b/src/AsyncRattus/Plugin/PrimExpr.hs
@@ -90,7 +90,6 @@
 isPrimExpr :: Expr Var -> Maybe PrimInfo
 isPrimExpr expr = isPrimExpr' expr >>= validatePartialPrimInfo
 
--- App (App (App (App f type) arg) Type2) arg2
 isPrimExpr' :: Expr Var -> Maybe PartialPrimInfo
 isPrimExpr' (App e (Type t)) = case mPPI of
   Just pPI@(PartialPrimInfo {typeArgs = tArgs}) -> Just pPI {typeArgs = t : tArgs}
diff --git a/src/AsyncRattus/Plugin/ScopeCheck.hs b/src/AsyncRattus/Plugin/ScopeCheck.hs
--- a/src/AsyncRattus/Plugin/ScopeCheck.hs
+++ b/src/AsyncRattus/Plugin/ScopeCheck.hs
@@ -25,33 +25,15 @@
 
 import Prelude hiding ((<>))
 
-#if __GLASGOW_HASKELL__ >= 902
 import GHC.Parser.Annotation
-#endif
-
-#if __GLASGOW_HASKELL__ >= 900
 import GHC.Plugins
 import GHC.Tc.Types
 import GHC.Data.Bag
 import GHC.Tc.Types.Evidence
-#else
-import GhcPlugins
-import TcRnTypes
-import TcEvidence
-import Bag
-#endif
-
-#if __GLASGOW_HASKELL__ >= 810
 import GHC.Hs.Extension
 import GHC.Hs.Expr
 import GHC.Hs.Pat
 import GHC.Hs.Binds
-#else 
-import HsExtension
-import HsExpr
-import HsPat
-import HsBinds
-#endif
 
 import Data.Graph
 import qualified Data.Set as Set
@@ -182,7 +164,7 @@
 
 
 
-#if __GLASGOW_HASKELL__ >= 902
+
 getLocAnn' :: SrcSpanAnn' b -> SrcSpan
 getLocAnn' = locA
 
@@ -190,15 +172,7 @@
 updateLoc :: SrcSpanAnn' b -> (GetCtxt => a) -> (GetCtxt => a)
 updateLoc src = modifyCtxt (\c -> c {srcLoc = getLocAnn' src})
 
-#else
-getLocAnn' :: SrcSpan -> SrcSpan
-getLocAnn' s = s
 
-
-updateLoc :: SrcSpan -> (GetCtxt => a) -> (GetCtxt => a)
-updateLoc src = modifyCtxt (\c -> c {srcLoc = src})
-#endif
-
 -- | Check all definitions in the given module. If Scope errors are
 -- found, the current execution is halted with 'exitFailure'.
 checkAll :: TcGblEnv -> TcM ()
@@ -240,12 +214,8 @@
 instance Scope a => Scope (GenLocated SrcSpan a) where
   check (L l x) =  (\c -> c {srcLoc = l}) `modifyCtxt` check x
 
-
-#if __GLASGOW_HASKELL__ >= 902
 instance Scope a => Scope (GenLocated (SrcSpanAnn' b) a) where
   check (L l x) =  updateLoc l $ check x
-#endif
-
   
 instance Scope a => Scope (Bag a) where
   check bs = fmap and (mapM check (bagToList bs))
@@ -256,38 +226,22 @@
 
 instance Scope (Match GhcTc (GenLocated SrcAnno (HsExpr GhcTc))) where
   check Match{m_pats=ps,m_grhss=rhs} = addVars (getBV ps) `modifyCtxt` check rhs
-#if __GLASGOW_HASKELL__ < 900
-  check XMatch{} = return True
-#endif
 
 instance Scope (Match GhcTc (GenLocated SrcAnno (HsCmd GhcTc))) where
   check Match{m_pats=ps,m_grhss=rhs} = addVars (getBV ps) `modifyCtxt` check rhs
-#if __GLASGOW_HASKELL__ < 900
-  check XMatch{} = return True
-#endif
 
 
 instance Scope (MatchGroup GhcTc (GenLocated SrcAnno (HsExpr GhcTc))) where
   check MG {mg_alts = alts} = check alts
-#if __GLASGOW_HASKELL__ < 900
-  check XMatchGroup {} = return True
-#endif
 
 
 instance Scope (MatchGroup GhcTc (GenLocated SrcAnno (HsCmd GhcTc))) where
   check MG {mg_alts = alts} = check alts
-#if __GLASGOW_HASKELL__ < 900
-  check XMatchGroup {} = return True
-#endif
 
 
 instance Scope a => ScopeBind (StmtLR GhcTc GhcTc a) where
   checkBind (LastStmt _ b _ _) =  ( , Set.empty) <$> check b
-#if __GLASGOW_HASKELL__ >= 900
   checkBind (BindStmt _ p b) = do
-#else
-  checkBind (BindStmt _ p b _ _) = do
-#endif
     let vs = getBV p
     let c' = addVars vs ?ctxt
     r <- setCtxt c' (check b)
@@ -298,9 +252,6 @@
   checkBind TransStmt{} = notSupported "monad comprehensions"
   checkBind ApplicativeStmt{} = notSupported "applicative do notation"
   checkBind RecStmt{} = notSupported "recursive do notation"
-#if __GLASGOW_HASKELL__ < 900
-  checkBind XStmtLR {} = return (True,Set.empty)
-#endif
 
 instance ScopeBind a => ScopeBind [a] where
   checkBind [] = return (True,Set.empty)
@@ -312,19 +263,14 @@
 instance ScopeBind a => ScopeBind (GenLocated SrcSpan a) where
   checkBind (L l x) =  (\c -> c {srcLoc = l}) `modifyCtxt` checkBind x
 
-#if __GLASGOW_HASKELL__ >= 902
 instance ScopeBind a => ScopeBind (GenLocated (SrcSpanAnn' b) a) where
   checkBind (L l x) =  updateLoc l $ checkBind x
-#endif
 
 instance Scope a => Scope (GRHS GhcTc a) where
   check (GRHS _ gs b) = do
     (r, vs) <- checkBind gs
     r' <- addVars vs `modifyCtxt`  (check b)
     return (r && r')
-#if __GLASGOW_HASKELL__ < 900
-  check XGRHS{} = return True
-#endif
 
 checkRec :: GetCtxt => LHsBindLR GhcTc GhcTc -> CheckM Bool
 checkRec b =  liftM2 (&&) (checkPatBind b) (check b)
@@ -365,11 +311,7 @@
                    }          
 
 
-#if __GLASGOW_HASKELL__ >= 902
 instance ScopeBind (SCC (GenLocated SrcSpanAnnA (HsBindLR  GhcTc GhcTc), Set Var)) where
-#else
-instance ScopeBind (SCC (LHsBindLR GhcTc GhcTc, Set Var)) where
-#endif
   checkBind (AcyclicSCC (b,vs)) = (, vs) <$> check b
   checkBind (CyclicSCC bs) = checkRecursiveBinds (map fst bs) (foldMap snd bs)
   
@@ -399,11 +341,7 @@
 
 
 -- Check nested bindings
-#if __GLASGOW_HASKELL__ >= 902
 instance ScopeBind (RecFlag, Bag (GenLocated SrcSpanAnnA (HsBindLR GhcTc GhcTc))) where
-#else
-instance ScopeBind (RecFlag, LHsBinds GhcTc) where
-#endif
   checkBind (NonRecursive, bs)  = checkBind $ bagToList bs
   checkBind (Recursive, bs) = checkRecursiveBinds bs' (foldMap getAllBV bs')
     where bs' = bagToList bs
@@ -413,33 +351,20 @@
   checkBind (HsValBinds _ bs) = checkBind bs
   checkBind HsIPBinds {} = notSupported "implicit parameters"
   checkBind EmptyLocalBinds{} = return (True,Set.empty)
-#if __GLASGOW_HASKELL__ < 900
-  checkBind XHsLocalBindsLR{} = return (True,Set.empty)
-#endif
 
-#if __GLASGOW_HASKELL__ >= 902
 type SrcAnno = SrcSpanAnnA
-#else
-type SrcAnno = SrcSpan
-#endif
   
 instance Scope (GRHSs GhcTc (GenLocated SrcAnno (HsExpr GhcTc))) where
   check GRHSs{grhssGRHSs = rhs, grhssLocalBinds = lbinds} = do
     (l,vs) <- checkBind lbinds
     r <- addVars vs `modifyCtxt` (check rhs)
     return (r && l)
-#if __GLASGOW_HASKELL__ < 900
-  check XGRHSs{} = return True
-#endif
 
 instance Scope (GRHSs GhcTc (GenLocated SrcAnno (HsCmd GhcTc))) where
   check GRHSs{grhssGRHSs = rhs, grhssLocalBinds = lbinds} = do
     (l,vs) <- checkBind lbinds
     r <- addVars vs `modifyCtxt` (check rhs)
     return (r && l)
-#if __GLASGOW_HASKELL__ < 900
-  check XGRHSs{} = return True
-#endif
 
 instance Show Var where
   show v = getOccString v
@@ -571,13 +496,9 @@
   check (NegApp _ e _) = check e
   check (ExplicitSum _ _ _ e) = check e
   check (HsMultiIf _ e) = check e
-#if __GLASGOW_HASKELL__ >= 902
   check (ExplicitList _ e) = check e
   check HsProjection {} = return True
   check HsGetField {gf_expr = e} = check e
-#else
-  check (ExplicitList _ _ e) = check e
-#endif
   check RecordUpd { rupd_expr = e, rupd_flds = fs} = (&&) <$> check e <*> check fs
   check RecordCon { rcon_flds = f} = check f
   check (ArithSeq _ _ e) = check e
@@ -594,35 +515,13 @@
 #if __GLASGOW_HASKELL__ >= 906
   check (HsAppType _ e _ _) = check e
   check (ExprWithTySig _ e _) = check e
-#elif __GLASGOW_HASKELL__ >= 808
+#else
   check (HsAppType _ e _) = check e
   check (ExprWithTySig _ e _) = check e
-#else
-  check (HsAppType _ e)  = check e
-  check (ExprWithTySig _ e) = check e
 #endif
-
-#if __GLASGOW_HASKELL__ >= 900
   check (HsPragE _ _ e) = check e
   check (HsIf _ e1 e2 e3) = and <$> mapM check [e1,e2,e3]
-#else
-  check (HsSCC _ _ _ e) = check e
-  check (HsCoreAnn _ _ _ e) = check e
-  check (HsTickPragma _ _ _ _ e) = check e
-  check (HsWrap _ _ e) = check e
-  check (HsIf _ _ e1 e2 e3) = and <$> mapM check [e1,e2,e3]
-#endif
-#if __GLASGOW_HASKELL__ < 810
-  check HsArrApp{} = impossible
-  check HsArrForm{} = impossible
-  check EWildPat{} = impossible
-  check EAsPat{} = impossible
-  check EViewPat{} = impossible
-  check ELazyPat{} = impossible
 
-impossible :: GetCtxt => TcM Bool
-impossible = printMessageCheck SevError "This syntax should never occur after typechecking"
-#endif
 
 instance (Scope a, Scope b) => Scope (Either a b) where
   check (Left x) = check x
@@ -636,7 +535,6 @@
 #endif
 
 
-#if __GLASGOW_HASKELL__ >= 900
 instance Scope XXExprGhcTc where
   check (WrapExpr (HsWrap _ e)) = check e
   check (ExpansionExpr (HsExpanded _ e)) = check e
@@ -645,19 +543,9 @@
   check (HsTick _ e) = check e
   check (HsBinTick _ _ e) = check e
 #endif
-#elif __GLASGOW_HASKELL__ >= 810
-instance Scope NoExtCon where
-  check _ = return True
-#else
-instance Scope NoExt where
-  check _ = return True
-#endif
 
 instance Scope (HsCmdTop GhcTc) where
   check (HsCmdTop _ e) = check e
-#if __GLASGOW_HASKELL__ < 900
-  check XCmdTop{} = return True
-#endif
   
 instance Scope (HsCmd GhcTc) where
   check (HsCmdArrApp _ e1 e2 _ _) = (&&) <$> check e1 <*> check e2
@@ -671,9 +559,7 @@
   check (HsCmdLet _ _ bs _ e) = do
 #else
   check (HsCmdPar _ e) = check e
-#if __GLASGOW_HASKELL__ >= 900
   check (HsCmdLamCase _ e) = check e
-#endif
   check (HsCmdLet _ bs e) = do
 #endif
     (l,vs) <- checkBind bs
@@ -682,12 +568,7 @@
 
   check (HsCmdCase _ e1 e2) = (&&) <$> check e1 <*> check e2
   check (HsCmdIf _ _ e1 e2 e3) = (&&) <$> ((&&) <$> check e1 <*> check e2) <*> check e3
-#if __GLASGOW_HASKELL__ >= 900
   check (XCmd (HsWrap _ e)) = check e
-#else
-  check (HsCmdWrap _ _ e) = check e
-  check XCmd{} = return True
-#endif
 
 
 instance Scope (ArithSeqInfo GhcTc) where
@@ -712,9 +593,6 @@
 instance Scope (HsTupArg GhcTc) where
   check (Present _ e) = check e
   check Missing{} = return True
-#if __GLASGOW_HASKELL__ < 900
-  check XTupArg{} = return True
-#endif
 
 instance Scope (HsBindLR GhcTc GhcTc) where
 #if __GLASGOW_HASKELL__ >= 904
@@ -726,11 +604,7 @@
       where mod c = c { stableTypes= stableTypes c `Set.union`
                         Set.fromList (mapMaybe (isStableConstr . varType) ev)}
   check FunBind{fun_matches= matches, fun_id = L _ v,
-#if __GLASGOW_HASKELL__ >= 900
                 fun_ext = wrapper} =
-#else
-                fun_co_fn = wrapper} =
-#endif
       mod `modifyCtxt` check matches
     where mod c = c { stableTypes= stableTypes c `Set.union`
                       Set.fromList (stableConstrFromWrapper' wrapper)  `Set.union`
@@ -738,9 +612,6 @@
   check PatBind{pat_lhs = lhs, pat_rhs=rhs} = addVars (getBV lhs) `modifyCtxt` check rhs
   check VarBind{var_rhs = rhs} = check rhs
   check PatSynBind {} = return True -- pattern synonyms are not supported
-#if __GLASGOW_HASKELL__ < 900
-  check XHsBindsLR {} = return True
-#endif
 
 
 -- | Checks whether the given type is a type constraint of the form
@@ -778,11 +649,7 @@
 -- of type variables @[a1,...,am]@ for which there is a constraint
 -- @Stable ai@ among @C1, ... Cn@.
 extractStableConstr :: Type -> [TyVar]
-#if __GLASGOW_HASKELL__ >= 900
 extractStableConstr  = mapMaybe isStableConstr . map irrelevantMult . fst . splitFunTys . snd . splitForAllTys'
-#else
-extractStableConstr  = mapMaybe isStableConstr . fst . splitFunTys . snd . splitForAllTys'
-#endif
 
 
 getSCCLoc :: SCC (LHsBindLR  GhcTc GhcTc, Set Var) -> SrcSpan
@@ -914,22 +781,13 @@
   isPrimExpr' (HsVar _ (L _ v)) = fmap (,v) (isPrim v)
 #if __GLASGOW_HASKELL__ >= 906
   isPrimExpr' (HsAppType _ e _ _) = isPrimExpr e
-#elif __GLASGOW_HASKELL__ >= 808
-  isPrimExpr' (HsAppType _ e _) = isPrimExpr e
 #else
-  isPrimExpr' (HsAppType _ e)   = isPrimExpr e
+  isPrimExpr' (HsAppType _ e _) = isPrimExpr e
 #endif
 
-#if __GLASGOW_HASKELL__ < 900
-  isPrimExpr' (HsSCC _ _ _ e) = isPrimExpr e
-  isPrimExpr' (HsCoreAnn _ _ _ e) = isPrimExpr e
-  isPrimExpr' (HsTickPragma _ _ _ _ e) = isPrimExpr e
-  isPrimExpr' (HsWrap _ _ e) = isPrimExpr' e
-#else
   isPrimExpr' (XExpr (WrapExpr (HsWrap _ e))) = isPrimExpr' e
   isPrimExpr' (XExpr (ExpansionExpr (HsExpanded _ e))) = isPrimExpr' e
   isPrimExpr' (HsPragE _ _ e) = isPrimExpr e
-#endif
 #if __GLASGOW_HASKELL__ < 904
   isPrimExpr' (HsTick _ _ e) = isPrimExpr e
   isPrimExpr' (HsBinTick _ _ _ e) = isPrimExpr e
diff --git a/src/AsyncRattus/Plugin/StableSolver.hs b/src/AsyncRattus/Plugin/StableSolver.hs
--- a/src/AsyncRattus/Plugin/StableSolver.hs
+++ b/src/AsyncRattus/Plugin/StableSolver.hs
@@ -12,7 +12,6 @@
 
 import Prelude hiding ((<>))
 
-#if __GLASGOW_HASKELL__ >= 900
 import GHC.Plugins
   (Type, Var, CommandLineOption,tyConSingleDataCon,
    mkCoreConApps,getTyVar_maybe)
@@ -20,21 +19,7 @@
 import GHC.Tc.Types.Evidence
 import GHC.Core.Class
 import GHC.Tc.Types
-#else
-import GhcPlugins
-  (Type, Var, CommandLineOption,tyConSingleDataCon,
-   mkCoreConApps,getTyVar_maybe)
-import CoreSyn
-import TcEvidence
-import Class
-import TcRnTypes
-#endif
-
-#if __GLASGOW_HASKELL__ >= 900
 import GHC.Tc.Types.Constraint
-#elif __GLASGOW_HASKELL__ >= 810
-import Constraint
-#endif
 
 import Data.Set (Set)
 import qualified Data.Set as Set
diff --git a/src/AsyncRattus/Plugin/Strictify.hs b/src/AsyncRattus/Plugin/Strictify.hs
--- a/src/AsyncRattus/Plugin/Strictify.hs
+++ b/src/AsyncRattus/Plugin/Strictify.hs
@@ -5,15 +5,8 @@
 import Prelude hiding ((<>))
 import AsyncRattus.Plugin.Utils
 
-#if __GLASGOW_HASKELL__ >= 900
 import GHC.Plugins
-#else
-import GhcPlugins
-#endif
-
-#if __GLASGOW_HASKELL__ >= 902
 import GHC.Types.Tickish
-#endif
 
 data SCxt = SCxt {srcSpan :: SrcSpan, checkStrictData :: Bool}
 
diff --git a/src/AsyncRattus/Plugin/Utils.hs b/src/AsyncRattus/Plugin/Utils.hs
--- a/src/AsyncRattus/Plugin/Utils.hs
+++ b/src/AsyncRattus/Plugin/Utils.hs
@@ -48,20 +48,10 @@
 #else
 import Data.IORef (readIORef)
 #endif  
-#if __GLASGOW_HASKELL__ >= 902
-
 import GHC.Utils.Logger
-#endif
-
-#if __GLASGOW_HASKELL__ >= 900
 import GHC.Plugins
 import GHC.Utils.Error
 import GHC.Utils.Monad
-#else
-import GhcPlugins
-import ErrUtils
-import MonadUtils
-#endif
 
 
 import GHC.Types.Name.Cache (NameCache(nsNames), lookupOrigNameCache, OrigNameCache)
@@ -101,14 +91,9 @@
 repSplitAppTys = splitAppTysNoView
 #endif
  
-#if __GLASGOW_HASKELL__ >= 902
+
 printMessage :: (HasDynFlags m, MonadIO m, HasLogger m) =>
                 Severity -> SrcSpan -> SDoc -> m ()
-#else
-printMessage :: (HasDynFlags m, MonadIO m) =>
-                Severity -> SrcSpan -> MsgDoc -> m ()
-#endif
-
 printMessage sev loc doc = do
 #if __GLASGOW_HASKELL__ >= 908
   logger <- getLogger
@@ -122,27 +107,14 @@
   logger <- getLogger
   liftIO $ putLogMsg logger (logFlags logger)
     (MCDiagnostic sev (if sev == SevError then ErrorWithoutFlag else WarningWithoutFlag)) loc doc
-#elif __GLASGOW_HASKELL__ >= 902
+#else
    dflags <- getDynFlags
    logger <- getLogger
    liftIO $ putLogMsg logger dflags NoReason sev loc doc
-#elif __GLASGOW_HASKELL__ >= 900  
-  dflags <- getDynFlags
-  liftIO $ putLogMsg dflags NoReason sev loc doc
-#else
-  dflags <- getDynFlags
-  let sty = case sev of
-              SevError   -> defaultErrStyle dflags
-              SevWarning -> defaultErrStyle dflags
-              SevDump    -> defaultDumpStyle dflags
-              _          -> defaultUserStyle dflags
-  liftIO $ putLogMsg dflags NoReason sev loc sty doc
 #endif
 
-#if __GLASGOW_HASKELL__ >= 902
 instance Ord FastString where
    compare = uniqCompareFS
-#endif
 
 {-
 ******************************************************
@@ -282,6 +254,8 @@
       case getNameModule con of
         Nothing -> False
         Just (name,mod)
+          | mod == "GHC.Num.Integer" && name == "Integer" -> True
+          | mod == "Data.Text.Internal" && name == "Text" -> True
           -- If it's a Rattus type constructor check if it's a box
           | isRattModule mod && name == "Box" -> True
             -- If its a built-in type check the set of stable built-in types
@@ -293,8 +267,7 @@
             case algTyConRhs con of
               DataTyCon {data_cons = cons, is_enum = enum}
                 | enum -> True
-                | and $ concatMap (map isSrcStrict'
-                                   . dataConSrcBangs) $ cons ->
+                | all hasStrictArgs cons ->
                   and  (map check cons)
                 | otherwise -> False
                 where check con = case dataConInstSig con args of
@@ -308,12 +281,8 @@
 isStrict :: Type -> Bool
 isStrict t = isStrictRec 0 Set.empty t
 
-#if __GLASGOW_HASKELL__ >= 902
 splitForAllTys' :: Type -> ([TyCoVar], Type)
 splitForAllTys' = splitForAllTyCoVars
-#else
-splitForAllTys' = splitForAllTys
-#endif
 
 -- | Check whether the given type is stable. This check may use
 -- 'Stable' constraints from the context.
@@ -349,7 +318,7 @@
             case algTyConRhs con of
               DataTyCon {data_cons = cons, is_enum = enum}
                 | enum -> True
-                | and $ (map (areSrcStrict args)) $ cons ->
+                | all hasStrictArgs cons ->
                   and  (map check cons)
                 | otherwise -> False
                 where check con = case dataConInstSig con args of
@@ -363,16 +332,8 @@
 
 
 
-areSrcStrict :: [Type] -> DataCon -> Bool
-areSrcStrict args con = and (zipWith check tys (dataConSrcBangs con))
-  where (_, _,tys) = dataConInstSig con args
-        check _ b = isSrcStrict' b
-
-isSrcStrict' :: HsSrcBang -> Bool
-isSrcStrict' (HsSrcBang _ _ SrcStrict) = True
-isSrcStrict' (HsSrcBang _ SrcUnpack _) = True
-isSrcStrict' _ =  False
-
+hasStrictArgs :: DataCon -> Bool
+hasStrictArgs con = all isBanged (dataConImplBangs con)
 
 userFunction :: Var -> Bool
 userFunction v
@@ -392,48 +353,26 @@
     _ -> False
 
 mkSysLocalFromVar :: MonadUnique m => FastString -> Var -> m Id
-#if __GLASGOW_HASKELL__ >= 900
-
 mkSysLocalFromVar lit v = mkSysLocalM lit (varMult v) (varType v)
-#else
-mkSysLocalFromVar lit v = mkSysLocalM lit (varType v)
-#endif
  
 mkSysLocalFromExpr :: MonadUnique m => FastString -> CoreExpr -> m Id
-#if __GLASGOW_HASKELL__ >= 900
 mkSysLocalFromExpr lit e = mkSysLocalM lit oneDataConTy (exprType e)
-#else
-mkSysLocalFromExpr lit e = mkSysLocalM lit (exprType e)
-#endif
  
  
 fromRealSrcSpan :: RealSrcSpan -> SrcSpan
 #if __GLASGOW_HASKELL__ >= 904
 fromRealSrcSpan span = RealSrcSpan span Strict.Nothing
-#elif __GLASGOW_HASKELL__ >= 900
-fromRealSrcSpan span = RealSrcSpan span Nothing
 #else
-fromRealSrcSpan span = RealSrcSpan span
+fromRealSrcSpan span = RealSrcSpan span Nothing
 #endif
 
-#if __GLASGOW_HASKELL__ >= 900
 instance Ord SrcSpan where
   compare (RealSrcSpan s _) (RealSrcSpan t _) = compare s t
   compare RealSrcSpan{} _ = LT
   compare _ _ = GT
-#endif
 
 noLocationInfo :: SrcSpan
-#if __GLASGOW_HASKELL__ >= 900
 noLocationInfo = UnhelpfulSpan UnhelpfulNoLocationInfo
-#else         
-noLocationInfo = UnhelpfulSpan "<no location info>"
-#endif
 
-#if __GLASGOW_HASKELL__ >= 902
 mkAlt c args e = Alt c args e
 getAlt (Alt c args e) = (c, args, e)
-#else
-mkAlt c args e = (c, args, e)
-getAlt alt = alt
-#endif
diff --git a/src/AsyncRattus/Signal.hs b/src/AsyncRattus/Signal.hs
--- a/src/AsyncRattus/Signal.hs
+++ b/src/AsyncRattus/Signal.hs
@@ -162,12 +162,6 @@
 const :: a -> Sig a
 const x = x ::: never
 
--- | Construct a signal by repeatedly applying a function to a given
--- start element. That is, @unfold (box f) x@ will produce the signal
--- @x ::: f x ::: f (f x) ::: ...@
--- unfold :: Stable a => Box (a -> a) -> a -> Sig a
--- unfold f x = x ::: delay (unfold f (unbox f x))
-
 -- | Similar to Haskell's 'scanl'.
 --
 -- > scan (box f) x (v1 ::: v2 ::: v3 ::: ... ) == (x `f` v1) ::: ((x `f` v1) `f` v2) ::: ...
@@ -178,7 +172,7 @@
 scan f acc (a ::: as) = acc' ::: delay (scan f acc' (adv as))
   where acc' = unbox f acc a
 
--- Like 'scan', but uses a delayed signal.
+-- | Like 'scan', but uses a delayed signal.
 scanAwait :: (Stable b) => Box (b -> a -> b) -> b -> O (Sig a) -> Sig b
 scanAwait f acc as = acc ::: delay (scan f acc (adv as))
 
@@ -348,12 +342,8 @@
     map p (scan f acc as) = scanMap f p acc as ;
 
   "zip/map" forall xs ys f.
-    map f (zip xs ys) = let f' = unbox f in zipWith (box (\ x y -> f' (x :* y))) xs ys
-#-}
-
+    map f (zip xs ys) = let f' = unbox f in zipWith (box (\ x y -> f' (x :* y))) xs ys;
 
-#if __GLASGOW_HASKELL__ >= 808
-{-# RULES
   "scan/scan" forall f g b c as.
     scan g c (scan f b as) =
       let f' = unbox f; g' = unbox g in
@@ -365,4 +355,4 @@
       scanMap (box (\ (b:*c) a -> let b' = f' (p' b) a in (b':* g' c b'))) (box snd') (b:*c) as ;
 
 #-}
-#endif
+
diff --git a/test/WellTyped.hs b/test/WellTyped.hs
--- a/test/WellTyped.hs
+++ b/test/WellTyped.hs
@@ -7,6 +7,7 @@
 import AsyncRattus
 import AsyncRattus.Signal
 import Data.Set as Set
+import Data.Text
 
 
 
@@ -121,6 +122,13 @@
 
 advUnderLambda :: O Int -> O (a -> Int)
 advUnderLambda y = delay (\_ -> adv y)
+
+
+stableText :: Text -> Sig Text -> Sig Text
+stableText = scan (box append) 
+
+stableInteger :: Integer -> Sig Integer -> Sig Integer
+stableInteger = scan (box (+)) 
 
 
 dblAdv :: O (O a) -> O (O a)