diff --git a/cimple.cabal b/cimple.cabal
--- a/cimple.cabal
+++ b/cimple.cabal
@@ -1,5 +1,5 @@
 name:          cimple
-version:       0.0.24
+version:       0.0.25
 synopsis:      Simple C-like programming language
 homepage:      https://toktok.github.io/
 license:       GPL-3
diff --git a/src/Language/Cimple.hs b/src/Language/Cimple.hs
--- a/src/Language/Cimple.hs
+++ b/src/Language/Cimple.hs
@@ -5,16 +5,17 @@
     , removeSloc
     ) where
 
-import           Control.Monad.State.Strict (State)
-import qualified Control.Monad.State.Strict as State
-import           Data.Text                  (Text)
+import           Control.Monad.State.Strict  (State)
+import qualified Control.Monad.State.Strict  as State
+import           Data.Text                   (Text)
 
-import           Language.Cimple.Annot      as X
-import           Language.Cimple.Ast        as X
-import           Language.Cimple.Lexer      as X
-import           Language.Cimple.MapAst     as X
-import           Language.Cimple.Parser     as X
-import           Language.Cimple.Tokens     as X
+import           Language.Cimple.Annot       as X
+import           Language.Cimple.Ast         as X
+import           Language.Cimple.DescribeAst as X
+import           Language.Cimple.Lexer       as X
+import           Language.Cimple.MapAst      as X
+import           Language.Cimple.Parser      as X
+import           Language.Cimple.Tokens      as X
 
 type DefaultActions a = X.IdentityActions (State a) Text
 
diff --git a/src/Language/Cimple/Ast.hs b/src/Language/Cimple/Ast.hs
--- a/src/Language/Cimple/Ast.hs
+++ b/src/Language/Cimple/Ast.hs
@@ -110,6 +110,7 @@
     | TyNullable a
     | TyPointer a
     | TyStruct lexeme
+    | TyUnion lexeme
     | TyFunc lexeme
     | TyStd lexeme
     | TyUserDefined lexeme
diff --git a/src/Language/Cimple/DescribeAst.hs b/src/Language/Cimple/DescribeAst.hs
--- a/src/Language/Cimple/DescribeAst.hs
+++ b/src/Language/Cimple/DescribeAst.hs
@@ -146,9 +146,9 @@
 describeExpected options
     | wants ["break", "const", "continue", "ID_CONST", "VLA"] = "statement or declaration"
     | wants ["ID_FUNC_TYPE", "non_null", "static", "'#include'"] = "top-level declaration or definition"
-    | options == ["ID_FUNC_TYPE", "ID_STD_TYPE", "ID_SUE_TYPE", "struct", "void"] = "top-level type specifier"
-    | options == ["ID_STD_TYPE", "ID_SUE_TYPE", "struct", "void"] = "type specifier"
-    | options == ["ID_STD_TYPE", "ID_SUE_TYPE", "bitwise", "const", "force", "struct", "void"] = "type specifier"
+    | options == ["ID_FUNC_TYPE", "ID_STD_TYPE", "ID_SUE_TYPE", "struct", "union", "void"] = "top-level type specifier"
+    | options == ["ID_STD_TYPE", "ID_SUE_TYPE", "struct", "union", "void"] = "type specifier"
+    | options == ["ID_STD_TYPE", "ID_SUE_TYPE", "bitwise", "const", "force", "struct", "union", "void"] = "type specifier"
     | options == ["ID_CONST", "ID_VAR", "LIT_CHAR", "LIT_FALSE", "LIT_INTEGER", "'{'"] = "constant or literal"
     | ["ID_FUNC_TYPE", "ID_STD_TYPE", "ID_SUE_TYPE", "ID_VAR"] `isPrefixOf` options = "type specifier or variable name"
     | ["ID_FUNC_TYPE", "ID_STD_TYPE", "ID_SUE_TYPE", "bitwise", "const"] `isPrefixOf` options = "type specifier"
diff --git a/src/Language/Cimple/MapAst.hs b/src/Language/Cimple/MapAst.hs
--- a/src/Language/Cimple/MapAst.hs
+++ b/src/Language/Cimple/MapAst.hs
@@ -343,6 +343,8 @@
             Fix <$> (TyPointer <$> recurse ty)
         TyStruct name ->
             Fix <$> (TyStruct <$> recurse name)
+        TyUnion name ->
+            Fix <$> (TyUnion <$> recurse name)
         TyFunc name ->
             Fix <$> (TyFunc <$> recurse name)
         TyStd name ->
diff --git a/src/Language/Cimple/Parser.y b/src/Language/Cimple/Parser.y
--- a/src/Language/Cimple/Parser.y
+++ b/src/Language/Cimple/Parser.y
@@ -695,6 +695,7 @@
 GlobalLeafType :: { NonTerm }
 GlobalLeafType
 :	struct ID_SUE_TYPE					{ Fix $ TyStruct $2 }
+|	union ID_SUE_TYPE					{ Fix $ TyUnion $2 }
 |	void							{ Fix $ TyStd $1 }
 |	ID_STD_TYPE						{ Fix $ TyStd $1 }
 |	ID_SUE_TYPE						{ Fix $ TyUserDefined $1 }
diff --git a/src/Language/Cimple/Pretty.hs b/src/Language/Cimple/Pretty.hs
--- a/src/Language/Cimple/Pretty.hs
+++ b/src/Language/Cimple/Pretty.hs
@@ -424,6 +424,7 @@
     TyStd         l  -> dullgreen $ ppLexeme l
     TyFunc        l  -> dullgreen $ ppLexeme l
     TyStruct      l  -> kwStruct <+> dullgreen (ppLexeme l)
+    TyUnion       l  -> kwUnion <+> dullgreen (ppLexeme l)
 
     ExternC decls ->
         dullmagenta (pretty "#ifdef __cplusplus") <$$>
diff --git a/src/Language/Cimple/TraverseAst.hs b/src/Language/Cimple/TraverseAst.hs
--- a/src/Language/Cimple/TraverseAst.hs
+++ b/src/Language/Cimple/TraverseAst.hs
@@ -442,6 +442,8 @@
             recurse ty
         TyStruct name ->
             recurse name
+        TyUnion name ->
+            recurse name
         TyFunc name ->
             recurse name
         TyStd name ->