diff --git a/scalie.cabal b/scalie.cabal
index fab9b99..10b8b2a 100644
--- a/scalie.cabal
+++ b/scalie.cabal
@@ -20,16 +20,16 @@ extra-source-files:
 library
   exposed-modules:
       Data.Map.Implicit
-      Language.Scalie.Ast.Definition
-      Language.Scalie.Ast.Expression
-      Language.Scalie.Ast.Module
-      Language.Scalie.Ast.Pattern
-      Language.Scalie.Ast.Provenance
-      Language.Scalie.Ast.Provenance.SourceLocation
       Language.Scalie.Bytecode.Instruction
       Language.Scalie.Bytecode.Object
       Language.Scalie.Bytecode.Object.Builder
       Language.Scalie.Compiler.Bytecode
+      Language.Scalie.Core.Definition
+      Language.Scalie.Core.Expression
+      Language.Scalie.Core.Module
+      Language.Scalie.Core.Pattern
+      Language.Scalie.Core.Provenance
+      Language.Scalie.Core.Provenance.SourceLocation
       Language.Scalie.Domain.Type
   other-modules:
       Paths_scalie
diff --git a/src/Language/Scalie/Bytecode/Object.hs b/src/Language/Scalie/Bytecode/Object.hs
index 326941e..acb158f 100644
--- a/src/Language/Scalie/Bytecode/Object.hs
+++ b/src/Language/Scalie/Bytecode/Object.hs
@@ -6,9 +6,9 @@
 module Language.Scalie.Bytecode.Object (Object(..)) where
 import Data.Kind (Type)
 import Data.Vector (Vector)
-import Language.Scalie.Ast.Provenance (Provenance)
+import Language.Scalie.Core.Provenance (Provenance)
 import Language.Scalie.Bytecode.Instruction (Instruction)
-import Language.Scalie.Ast.Provenance.SourceLocation (SourceLocation)
+import Language.Scalie.Core.Provenance.SourceLocation (SourceLocation)
 import Text.Show (Show)
 import Text.Read (Read)
 import Data.Semigroup (Semigroup)
diff --git a/src/Language/Scalie/Compiler/Bytecode.hs b/src/Language/Scalie/Compiler/Bytecode.hs
index 50a30ae..f81cc07 100644
--- a/src/Language/Scalie/Compiler/Bytecode.hs
+++ b/src/Language/Scalie/Compiler/Bytecode.hs
@@ -1,10 +1,10 @@
 {-# LANGUAGE Trustworthy #-} -- uses vector operations
 {-# LANGUAGE OverloadedRecordDot #-}
 module Language.Scalie.Compiler.Bytecode (EntryPoint, compile, CompilationError(..)) where
-import Language.Scalie.Ast.Module (Module (definitions))
+import Language.Scalie.Core.Module (Module (definitions))
 import Data.Text (Text)
-import Language.Scalie.Ast.Provenance (Provenance (value, Provenance, source))
-import Language.Scalie.Ast.Provenance.SourceLocation (SourceLocation)
+import Language.Scalie.Core.Provenance (Provenance (value, Provenance, source))
+import Language.Scalie.Core.Provenance.SourceLocation (SourceLocation)
 import Language.Scalie.Bytecode.Object qualified as Bytecode
 import Data.Kind (Type)
 import Data.Either (Either (Left, Right))
@@ -14,8 +14,8 @@ import Data.Function (($))
 import Data.Functor ((<$>))
 import Data.Map.Implicit qualified as ImplicitMap
 import Data.Maybe (Maybe(Nothing, Just))
-import Language.Scalie.Ast.Definition (Definition(body, name))
-import Language.Scalie.Ast.Expression (Expression(RawInt))
+import Language.Scalie.Core.Definition (Definition(body, name))
+import Language.Scalie.Core.Expression (Expression(RawInt))
 import Language.Scalie.Bytecode.Instruction qualified as Instruction
 
 -- | The name of the entrypoint function
diff --git a/src/Language/Scalie/Ast/Definition.hs b/src/Language/Scalie/Core/Definition.hs
similarity index 92%
rename from src/Language/Scalie/Ast/Definition.hs
rename to src/Language/Scalie/Core/Definition.hs
index b8ebb3d..8330ef5 100644
--- a/src/Language/Scalie/Ast/Definition.hs
+++ b/src/Language/Scalie/Core/Definition.hs
@@ -5,7 +5,7 @@
 {-# LANGUAGE UndecidableInstances #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE OverloadedRecordDot #-}
-module Language.Scalie.Ast.Definition (Definition(..)) where
+module Language.Scalie.Core.Definition (Definition(..)) where
 
 import Data.Kind (Type)
 import Data.Text (Text)
@@ -13,7 +13,7 @@ import Data.Text (Text)
 import Data.Map.Implicit (ImplicitKeyOf (KeyType, keyOf))
 
 import Language.Scalie.Domain.Type qualified as Scalie.Domain
-import Language.Scalie.Ast.Expression (Expression)
+import Language.Scalie.Core.Expression (Expression)
 import Text.Show (Show)
 import Text.Read (Read)
 import Data.Eq (Eq)
@@ -24,7 +24,7 @@ import Data.Text qualified as Text
 import Control.Category (Category((.)))
 import Test.QuickCheck.Modifiers (UnicodeString(getUnicodeString))
 import Data.Functor (Functor)
-import Language.Scalie.Ast.Provenance (Provenance (value))
+import Language.Scalie.Core.Provenance (Provenance (value))
 import Data.Functor.Identity (Identity)
 import Data.Maybe (Maybe)
 
@@ -33,7 +33,7 @@ import Data.Maybe (Maybe)
 -- >>> import Data.Functor.Identity (Identity(Identity))
 -- >>> import Data.Function (($))
 -- >>> :set -XOverloadedStrings
--- >>> import Language.Scalie.Ast.Expression qualified as Expression
+-- >>> import Language.Scalie.Core.Expression qualified as Expression
 -- >>> Definition (Identity Scalie.Domain.RawInt) (Identity "x") (Identity (Expression.RawInt 5))
 -- Definition {signature = Identity RawInt, name = Identity "x", body = Identity (RawInt 5)}
 --
diff --git a/src/Language/Scalie/Ast/Expression.hs b/src/Language/Scalie/Core/Expression.hs
similarity index 88%
rename from src/Language/Scalie/Ast/Expression.hs
rename to src/Language/Scalie/Core/Expression.hs
index 8ecf68e..1d7a05e 100644
--- a/src/Language/Scalie/Ast/Expression.hs
+++ b/src/Language/Scalie/Core/Expression.hs
@@ -1,6 +1,6 @@
 {-# LANGUAGE Safe #-}
 {-# LANGUAGE InstanceSigs #-}
-module Language.Scalie.Ast.Expression (Expression(..)) where
+module Language.Scalie.Core.Expression (Expression(..)) where
 
 import Prelude (Integer)
 import Data.Kind (Type)
diff --git a/src/Language/Scalie/Ast/Module.hs b/src/Language/Scalie/Core/Module.hs
similarity index 93%
rename from src/Language/Scalie/Ast/Module.hs
rename to src/Language/Scalie/Core/Module.hs
index 8d127aa..49c25c0 100644
--- a/src/Language/Scalie/Ast/Module.hs
+++ b/src/Language/Scalie/Core/Module.hs
@@ -3,10 +3,10 @@
 {-# LANGUAGE StandaloneDeriving #-} -- to specify contexts
 {-# LANGUAGE FlexibleContexts #-} -- 'non type-variable argument'
 {-# LANGUAGE UndecidableInstances #-} -- instance head no smaller...
-module Language.Scalie.Ast.Module (Module(..)) where
+module Language.Scalie.Core.Module (Module(..)) where
 
 import Data.Kind (Type)
-import Language.Scalie.Ast.Definition (Definition)
+import Language.Scalie.Core.Definition (Definition)
 import Data.Map.Implicit (ImplicitMap)
 import Text.Show (Show)
 import Text.Read (Read)
diff --git a/src/Language/Scalie/Ast/Pattern.hs b/src/Language/Scalie/Core/Pattern.hs
similarity index 92%
rename from src/Language/Scalie/Ast/Pattern.hs
rename to src/Language/Scalie/Core/Pattern.hs
index cd1b2e9..501ddd0 100644
--- a/src/Language/Scalie/Ast/Pattern.hs
+++ b/src/Language/Scalie/Core/Pattern.hs
@@ -1,6 +1,6 @@
 {-# LANGUAGE Safe #-}
 {-# LANGUAGE DerivingStrategies #-}
-module Language.Scalie.Ast.Pattern (Pattern(..)) where
+module Language.Scalie.Core.Pattern (Pattern(..)) where
 import Prelude (Integer)
 import Text.Show (Show)
 import Text.Read (Read)
diff --git a/src/Language/Scalie/Ast/Provenance.hs b/src/Language/Scalie/Core/Provenance.hs
similarity index 95%
rename from src/Language/Scalie/Ast/Provenance.hs
rename to src/Language/Scalie/Core/Provenance.hs
index 9c021c5..a39a889 100644
--- a/src/Language/Scalie/Ast/Provenance.hs
+++ b/src/Language/Scalie/Core/Provenance.hs
@@ -1,7 +1,7 @@
 {-# LANGUAGE Safe #-}
 {-# LANGUAGE InstanceSigs #-}
 {-# LANGUAGE DeriveTraversable #-} -- implies DeriveFunctor and DeriveFoldable
-module Language.Scalie.Ast.Provenance (Provenance(..)) where
+module Language.Scalie.Core.Provenance (Provenance(..)) where
 import Data.Kind (Type)
 import Text.Show (Show)
 import Text.Read (Read)
diff --git a/src/Language/Scalie/Ast/Provenance/SourceLocation.hs b/src/Language/Scalie/Core/Provenance/SourceLocation.hs
similarity index 72%
rename from src/Language/Scalie/Ast/Provenance/SourceLocation.hs
rename to src/Language/Scalie/Core/Provenance/SourceLocation.hs
index 5de2a01..ab1f76f 100644
--- a/src/Language/Scalie/Ast/Provenance/SourceLocation.hs
+++ b/src/Language/Scalie/Core/Provenance/SourceLocation.hs
@@ -1,5 +1,5 @@
 {-# LANGUAGE Safe #-}
-module Language.Scalie.Ast.Provenance.SourceLocation (SourceLocation(..)) where
+module Language.Scalie.Core.Provenance.SourceLocation (SourceLocation(..)) where
 import Data.Kind (Type)
 import Text.Show (Show)
 import Text.Read (Read)
diff --git a/test/Test/Data/Map/Implicit.hs b/test/Test/Data/Map/Implicit.hs
index 1c4cb3d..d9efede 100644
--- a/test/Test/Data/Map/Implicit.hs
+++ b/test/Test/Data/Map/Implicit.hs
@@ -8,7 +8,7 @@ import Text.Show (show)
 import Text.Read (read)
 import Data.Map.Implicit (ImplicitMap)
 import Data.Bool (Bool)
-import Language.Scalie.Ast.Definition (Definition)
+import Language.Scalie.Core.Definition (Definition)
 import Data.Functor.Identity (Identity)
 import Test.QuickCheck (Property, allProperties)
 import Data.String (String)