diff --git a/krakenGrammer.kgm b/krakenGrammer.kgm
index 4f0157e..2a12825 100644
--- a/krakenGrammer.kgm
+++ b/krakenGrammer.kgm
@@ -83,9 +83,8 @@ opt_parameter_list = parameter_list | ;
 parameter_list = parameter_list WS "," WS parameter | parameter ;
 parameter = boolean_expression ;
 
-def_nonterm = "def" ;
-obj_nonterm = "obj" ;
-type_def = def_nonterm WS identifier WS type | obj_nonterm WS identifier WS template_dec WS "{" WS declaration_block WS "}" | obj_nonterm WS identifier WS "{" WS declaration_block WS "}" | obj_nonterm WS identifier WS template_dec WS traits WS "{" WS declaration_block WS "}" | obj_nonterm WS identifier WS traits WS "{" WS declaration_block WS "}" ;
+obj_nonterm = "obj" | "uni" ;
+type_def = obj_nonterm WS identifier WS template_dec WS "{" WS declaration_block WS "}" | obj_nonterm WS identifier WS "{" WS declaration_block WS "}" | obj_nonterm WS identifier WS template_dec WS traits WS "{" WS declaration_block WS "}" | obj_nonterm WS identifier WS traits WS "{" WS declaration_block WS "}" ;
 
 declaration_block = declaration_statement line_end WS declaration_block | function WS declaration_block | declaration_statement line_end | function | ;
 traits = "\(" WS trait_list WS "\)" ;
diff --git a/stdlib/ast_nodes.krak b/stdlib/ast_nodes.krak
index 310b170..69bd3b2 100644
--- a/stdlib/ast_nodes.krak
+++ b/stdlib/ast_nodes.krak
@@ -190,13 +190,13 @@ obj identifier (Object) {
         return name == other.name && type == other.type && enclosing_scope == other.enclosing_scope
     }
 }
-fun ast_type_def_ptr(name: string): *ast_node {
-/*fun ast_type_def_ptr(name: ref string): *ast_node {*/
-    /*return ast_type_def_ptr(name, false)*/
-/*}*/
-/*fun ast_type_def_ptr(name: ref string, is_union: bool): *ast_node {*/
-    /*var to_ret.construct(name, is_union): type_def*/
-    var to_ret.construct(name): type_def
+/*fun ast_type_def_ptr(name: string): *ast_node {*/
+fun ast_type_def_ptr(name: ref string): *ast_node {
+    return ast_type_def_ptr(name, false)
+}
+fun ast_type_def_ptr(name: ref string, is_union: bool): *ast_node {
+    var to_ret.construct(name, is_union): type_def
+    /*var to_ret.construct(name): type_def*/
     var ptr = new<ast_node>()
     ptr->copy_construct(&ast_node::type_def(to_ret))
     return ptr
@@ -210,16 +210,16 @@ fun is_type_def(node: *ast_node): bool {
 obj type_def (Object) {
     var scope: map<string, vector<*ast_node>>
     var name: string
-    /*var is_union: bool*/
     var self_type: *type
     var variables: vector<*ast_node>
     var methods: vector<*ast_node>
-    /*fun construct(nameIn: ref string, is_unionIn: bool): *type_def  {*/
-    fun construct(nameIn: ref string): *type_def  {
+    var is_union: bool
+    fun construct(nameIn: ref string, is_unionIn: bool): *type_def  {
+    /*fun construct(nameIn: ref string): *type_def  {*/
     /*fun construct(nameIn: string): *type_def  {*/
         scope.construct()
         name.copy_construct(&nameIn)
-        /*is_union = is_unionIn*/
+        is_union = is_unionIn
         self_type = null<type>()
         variables.construct()
         methods.construct()
@@ -229,7 +229,7 @@ obj type_def (Object) {
         self_type = old->self_type
         scope.copy_construct(&old->scope)
         name.copy_construct(&old->name)
-        /*is_union = old->is_union*/
+        is_union = old->is_union
         variables.copy_construct(&old->variables)
         methods.copy_construct(&old->methods)
     }
@@ -244,8 +244,8 @@ obj type_def (Object) {
         copy_construct(&other)
     }
     fun operator==(other: ref type_def): bool {
-        /*return name == other.name && is_union == other.is_union && self_type == other.self_type && variables == other.variables && methods == other.methods*/
-        return name == other.name && self_type == other.self_type && variables == other.variables && methods == other.methods
+        return name == other.name && is_union == other.is_union && self_type == other.self_type && variables == other.variables && methods == other.methods
+        /*return name == other.name && self_type == other.self_type && variables == other.variables && methods == other.methods*/
     }
 }
 fun ast_adt_def_ptr(name: string): *ast_node {
diff --git a/stdlib/ast_transformation.krak b/stdlib/ast_transformation.krak
index 0623f3b..693e786 100644
--- a/stdlib/ast_transformation.krak
+++ b/stdlib/ast_transformation.krak
@@ -104,9 +104,9 @@ obj ast_transformation (Object) {
             return template
         } else {
             // pass in whether or not this is a union
-            /*var type_def_node = ast_type_def_ptr(name, concat_symbol_tree(get_node("obj_nonterm", child)) == "uni")*/
+            var type_def_node = ast_type_def_ptr(name, concat_symbol_tree(get_node("obj_nonterm", child)) == "uni")
             /*var type_def_node = ast_type_def_ptr(name, false)*/
-            var type_def_node = ast_type_def_ptr(name)
+            /*var type_def_node = ast_type_def_ptr(name)*/
             type_def_node->type_def.self_type = type_ptr(type_def_node, transform_traits(get_node("traits", child)))
             ast_to_syntax.set(type_def_node, child)
             add_to_scope("~enclosing_scope", scope, type_def_node)
diff --git a/stdlib/c_generator.krak b/stdlib/c_generator.krak
index fcf16fa..b769faa 100644
--- a/stdlib/c_generator.krak
+++ b/stdlib/c_generator.krak
@@ -443,16 +443,15 @@ obj c_generator (Object) {
             })
         })
         type_poset.get_sorted().for_each(fun(vert: *ast_node) {
-            /*var base_name = vert->type_def.name*/
             var base_name = get_name(vert)
             plain_typedefs += string("typedef ")
-            /*if (is_type_def(vert) && vert->type_def.is_union) {*/
-                /*plain_typedefs += "union "*/
-                /*structs += "union "*/
-            /*} else {*/
+            if (is_type_def(vert) && vert->type_def.is_union) {
+                plain_typedefs += "union "
+                structs += "union "
+            } else {
                 plain_typedefs += "struct "
                 structs += "struct "
-            /*}*/
+            }
             plain_typedefs += base_name + "_dummy " + base_name + ";\n"
             structs += base_name + "_dummy {\n"
             if (is_type_def(vert)) {