diff --git a/src/builtins/builtins.zig b/src/builtins/builtins.zig
index 9e2212af7..8ca941c27 100644
--- a/src/builtins/builtins.zig
+++ b/src/builtins/builtins.zig
@@ -32,6 +32,7 @@ const funcs = [_]C.HostFuncEntry{
     // Utils.
     func("bitcast_",       zErrFunc(bitcast)),
     func("copy_",          zErrFunc(copy)),
+    func("choicetag_",     zErrFunc(choicetag)),
     func("dump",           zErrFunc(dump)),
     func("eprint",         eprint),
     func("errorReport",    zErrFunc(errorReport)),
@@ -596,6 +597,16 @@ pub fn copy(vm: *cy.VM) anyerror!Value {
     return cy.value.shallowCopy(vm, type_id, val);
 }
 
+pub fn choicetag(vm: *cy.VM) anyerror!Value {
+    const tag_t: cy.TypeId = @intCast(vm.getInt(0));
+    const type_e = vm.sema.getType(tag_t);
+    if (type_e.kind != .enum_t) {
+        return error.InvalidArgument;
+    }
+    const choice_tag = vm.getValue(1).castHeapObject(*cy.heap.Object).getValue(0).asInt();
+    return cy.Value.initEnum(@intCast(tag_t), @intCast(choice_tag));
+}
+
 pub fn errorReport(vm: *cy.VM) anyerror!Value {
     const curFrameLen = vm.compactTrace.len;
 
diff --git a/src/builtins/builtins_vm.cy b/src/builtins/builtins_vm.cy
index ed6e55b19..b85d4e558 100644
--- a/src/builtins/builtins_vm.cy
+++ b/src/builtins/builtins_vm.cy
@@ -13,6 +13,13 @@ func copy[T](val T) T:
 
 @host -func copy_[T](type_id int, val T) T
 
+--| Returns the tag of a choice.
+--| TODO: This will be moved to `T.tag()`.
+func choicetag[T](choice T) T.Tag:
+    return choicetag_(typeid[T.Tag], choice)
+
+@host -func choicetag_[T](tag_t int, choice T) T.Tag
+
 --| Dumps a detailed description of a value.
 @host func dump(val any) void
 
diff --git a/src/module.zig b/src/module.zig
index 872fdfebc..b5c39a4b0 100644
--- a/src/module.zig
+++ b/src/module.zig
@@ -311,19 +311,19 @@ pub const ChunkExt = struct {
 
     pub fn reserveEnumType(c: *cy.Chunk, parent: *cy.Sym, name: []const u8, isChoiceType: bool, decl: *ast.EnumDecl) !*cy.sym.EnumType {
         const sym = try c.createEnumType(parent, name, isChoiceType, decl);
-        _ = try addUniqueSym(c, c.sym.getMod(), name, @ptrCast(sym), @ptrCast(decl));
+        _ = try addUniqueSym(c, parent.getMod().?, name, @ptrCast(sym), @ptrCast(decl));
         return sym;
     }
 
     pub fn reserveTraitType(c: *cy.Chunk, parent: *cy.Sym, name: []const u8, decl: *ast.TraitDecl) !*cy.sym.TraitType {
         const sym = try c.createTraitType(parent, name, decl);
-        _ = try addUniqueSym(c, c.sym.getMod(), name, @ptrCast(sym), @ptrCast(decl));
+        _ = try addUniqueSym(c, parent.getMod().?, name, @ptrCast(sym), @ptrCast(decl));
         return sym;
     }
 
     pub fn reserveObjectType(c: *cy.Chunk, parent: *cy.Sym, name: []const u8, decl: *ast.Node) !*cy.sym.ObjectType {
         const sym = try c.createObjectType(parent, name, decl);
-        _ = try addUniqueSym(c, c.sym.getMod(), name, @ptrCast(sym), decl);
+        _ = try addUniqueSym(c, parent.getMod().?, name, @ptrCast(sym), decl);
         return sym;
     }
 
diff --git a/src/sema.zig b/src/sema.zig
index 0df64757c..beb53a552 100644
--- a/src/sema.zig
+++ b/src/sema.zig
@@ -1654,7 +1654,11 @@ pub fn declareModuleAlias(c: *cy.Chunk, node: *ast.ImportStmt) !void {
 
 pub fn reserveEnum(c: *cy.Chunk, node: *ast.EnumDecl) !*cy.sym.EnumType {
     const name = c.ast.nodeString(node.name);
-    return c.reserveEnumType(@ptrCast(c.sym), name, node.isChoiceType, node);
+    const sym = try c.reserveEnumType(@ptrCast(c.sym), name, node.isChoiceType, node);
+    if (node.isChoiceType) {
+        _ = try c.reserveEnumType(@ptrCast(sym), "Tag", false, node);
+    }
+    return sym;
 }
 
 pub fn resolveEnumType(c: *cy.Chunk, sym: *cy.sym.EnumType, decl: *ast.EnumDecl) !void {
@@ -1666,6 +1670,11 @@ pub fn resolveEnumType(c: *cy.Chunk, sym: *cy.sym.EnumType, decl: *ast.EnumDecl)
     defer popResolveContext(c);
 
     try declareEnumMembers(c, sym, decl);
+
+    if (sym.isChoiceType) {
+        const tag_sym = sym.getMod().getSym("Tag").?.cast(.enum_t);
+        try declareEnumMembers(c, tag_sym, decl);
+    }
 }
 
 /// Explicit `decl` node for distinct type declarations. Must belong to `c`.
@@ -1677,7 +1686,7 @@ pub fn declareEnumMembers(c: *cy.Chunk, sym: *cy.sym.EnumType, decl: *ast.EnumDe
     for (decl.members, 0..) |member, i| {
         const mName = c.ast.nodeString(member.name);
         var payloadType: cy.TypeId = cy.NullId;
-        if (member.typeSpec != null) {
+        if (sym.isChoiceType and member.typeSpec != null) {
             payloadType = try resolveTypeSpecNode(c, member.typeSpec);
         }
         const modSymId = try c.declareEnumMember(@ptrCast(sym), mName, sym.type, sym.isChoiceType, @intCast(i), payloadType, member);
@@ -1948,6 +1957,9 @@ pub fn reserveTemplateVariant(c: *cy.Chunk, template: *cy.sym.Template, opt_head
             if (template == c.sema.option_tmpl) {
                 c.compiler.sema.types.items[sym.type].kind = .option;
             }
+            if (decl.isChoiceType) {
+                _ = try c.reserveEnumType(@ptrCast(sym), "Tag", false, decl);
+            }
             return @ptrCast(sym);
         },
         .distinct_t => {
diff --git a/src/sym.zig b/src/sym.zig
index 47e234e4d..918261923 100644
--- a/src/sym.zig
+++ b/src/sym.zig
@@ -1727,7 +1727,7 @@ pub const ChunkExt = struct {
         @as(*cy.Module, @ptrCast(&sym.mod)).* = cy.Module.init(c);
         c.compiler.sema.types.items[typeId] = .{
             .sym = @ptrCast(sym),
-            .kind = if (isChoiceType) .choice else .@"enum",
+            .kind = if (isChoiceType) .choice else .enum_t,
             .info = .{},
             .data = undefined,
         };
diff --git a/src/types.zig b/src/types.zig
index 65e4741d8..ac2b53a9a 100644
--- a/src/types.zig
+++ b/src/types.zig
@@ -20,7 +20,7 @@ pub const TypeKind = enum(u8) {
     float,
     object,
     host_object,
-    @"enum",
+    enum_t,
     choice,
     struct_t,
     option,
@@ -335,7 +335,7 @@ pub const SemaExt = struct {
         if (typeId < PrimitiveEnd) {
             return false;
         }
-        return s.types.items[typeId].kind == .@"enum";
+        return s.types.items[typeId].kind == .enum_t;
     }
 
     pub fn isChoiceType(s: *cy.Sema, typeId: TypeId) bool {
diff --git a/src/vm.zig b/src/vm.zig
index feb6e25f5..f6c75b33b 100644
--- a/src/vm.zig
+++ b/src/vm.zig
@@ -2073,7 +2073,7 @@ pub fn unbox(vm: *VM, val: Value, type_id: cy.TypeId) cy.Value {
 fn canInferArg(vm: *VM, arg: Value, target_t: cy.TypeId) bool {
     if (arg.getTypeId() == bt.TagLit) {
         const type_e = vm.c.types[target_t];
-        if (type_e.kind == .@"enum") {
+        if (type_e.kind == .enum_t) {
             const name = vm.syms.buf[arg.asSymbolId()].name;
             if (type_e.sym.cast(.enum_t).getMemberTag(name)) |value| {
                 _ = value;
@@ -2090,7 +2090,7 @@ fn canInferArg(vm: *VM, arg: Value, target_t: cy.TypeId) bool {
 fn inferArg(vm: *VM, arg: Value, target_t: cy.TypeId) ?Value {
     if (arg.getTypeId() == bt.TagLit) {
         const type_e = vm.c.types[target_t];
-        if (type_e.kind == .@"enum") {
+        if (type_e.kind == .enum_t) {
             const name = vm.syms.buf[arg.asSymbolId()].name;
             if (type_e.sym.cast(.enum_t).getMemberTag(name)) |value| {
                 return Value.initEnum(target_t, @intCast(value));
diff --git a/test/modules/core.cy b/test/modules/core.cy
index f7c8bebc1..7eb8eba21 100644
--- a/test/modules/core.cy
+++ b/test/modules/core.cy
@@ -31,6 +31,8 @@ foo()
 
 -- bool(), see truthy_test.cy
 
+-- choicetag(), see choice_type.cy
+
 -- copy()
 t.eq(copy(123), 123)
 type S:
diff --git a/test/types/choice_type.cy b/test/types/choice_type.cy
index 70eec4d9d..8f4d28963 100644
--- a/test/types/choice_type.cy
+++ b/test/types/choice_type.cy
@@ -92,4 +92,12 @@ var rect = Rectangle{width=123, height=234}
 s = Shape.rectangle(rect)
 test.assert(s.!rectangle == rect)
 
+-- Builtin choicetag.
+s = Shape.line(123)
+test.eq(choicetag(s), .line)
+
+-- Choice type also generates a enum `Tag` type.
+var tag = Shape.Tag.rectangle
+test.eq(tag, .rectangle)
+
 --cytest: pass
\ No newline at end of file