diff --git a/generator/registry-new.zig b/generator/registry-new.zig
index 200b841..32363ac 100644
--- a/generator/registry-new.zig
+++ b/generator/registry-new.zig
@@ -25,22 +25,22 @@ pub const Tag = struct {
 };
 
 pub const TypeInfo = union(enum) {
-    Struct: Container,
-    Union: Container,
-    Enum: Enum,
-    Bitmask: Bitmask,
-    Handle: Handle,
-    FnPtr: Command,
-    Command: Command,
-    Alias: []const u8, // Alias of another declaration
-    Pointer: Pointer,
-    Array: Array,
-    Opaque: void,
-    Foreign: Foreign
+    container: Container,
+    enumeration: Enum,
+    bitmask: Bitmask,
+    handle: Handle,
+    fn_ptr: Command,
+    command: Command,
+    alias: []const u8, // Alias of another declaration
+    pointer: Pointer,
+    array: Array,
+    opaque: void,
+    foreign: Foreign
 };
 
 pub const Container = struct {
     fields: []Declaration,
+    is_union: bool,
 };
 
 pub const Enum = struct {
diff --git a/generator/spec-c-parse.zig b/generator/spec-c-parse.zig
index 551c47d..7b1b98c 100644
--- a/generator/spec-c-parse.zig
+++ b/generator/spec-c-parse.zig
@@ -241,7 +241,7 @@ pub fn parseDeclaration(allocator: *Allocator, xctok: *XmlCTokenizer) !registry.
     if (tok.id != .type_name) return error.InvalidSyntax;
     const type_name = tok.text;
 
-    var type_info = registry.TypeInfo{.Alias = type_name};
+    var type_info = registry.TypeInfo{.alias = type_name};
 
     // Parse pointers
     type_info = try parsePointers(allocator, xctok, inner_is_const, type_info);
@@ -260,7 +260,7 @@ pub fn parseDeclaration(allocator: *Allocator, xctok: *XmlCTokenizer) !registry.
         const child = try allocator.create(registry.TypeInfo);
         child.* = type_info;
         type_info = .{
-            .Array = .{
+            .array = .{
                 .size = array_size,
                 .child = child,
             }
@@ -305,7 +305,7 @@ fn parsePointers(
         child.* = type_info;
 
         type_info = .{
-            .Pointer = .{
+            .pointer = .{
                 .size = .one, // set elsewhere
                 .is_const = is_const or (first_const),
                 .child = child,
diff --git a/generator/spec-parse.zig b/generator/spec-parse.zig
index 6837e25..0b324ab 100644
--- a/generator/spec-parse.zig
+++ b/generator/spec-parse.zig
@@ -87,7 +87,7 @@ fn parseForeigntype(ty: *xml.Element) !registry.Declaration {
 
     return registry.Declaration{
         .name = name,
-        .decl_type = .{.Foreign = .{.dependency = dependency}},
+        .decl_type = .{.foreign = .{.dependency = dependency}},
     };
 }
 
@@ -96,12 +96,12 @@ fn parseBitmaskType(ty: *xml.Element) !registry.Declaration {
         const alias = ty.getAttribute("alias") orelse return error.InvalidRegistry;
         return registry.Declaration{
             .name = name,
-            .decl_type = .{.Alias = alias},
+            .decl_type = .{.alias = alias},
         };
     } else {
         return registry.Declaration{
             .name = ty.getCharData("name") orelse return error.InvalidRegistry,
-            .decl_type = .{.Bitmask = .{.bits_enum = ty.getAttribute("requires")}},
+            .decl_type = .{.bitmask = .{.bits_enum = ty.getAttribute("requires")}},
         };
     }
 }
@@ -112,7 +112,7 @@ fn parseHandleType(ty: *xml.Element) !registry.Declaration {
         const alias = ty.getAttribute("alias") orelse return error.InvalidRegistry;
         return registry.Declaration{
             .name = name,
-            .decl_type = .{.Alias = alias},
+            .decl_type = .{.alias = alias},
         };
     } else {
         const name = ty.getCharData("name") orelse return error.InvalidRegistry;
@@ -125,7 +125,7 @@ fn parseHandleType(ty: *xml.Element) !registry.Declaration {
         return registry.Declaration{
             .name = name,
             .decl_type = .{
-                .Handle = .{
+                .handle = .{
                     .parent = ty.getAttribute("parent"),
                     .is_dispatchable = dispatchable,
                 }
@@ -144,7 +144,7 @@ fn parseBaseType(allocator: *Allocator, ty: *xml.Element) !registry.Declaration
         // macros, which is why this part is not built into the xml/c parser.
         return registry.Declaration{
             .name = name,
-            .decl_type = .{.Opaque = {}},
+            .decl_type = .{.opaque = {}},
         };
     }
 }
@@ -160,7 +160,7 @@ fn parseEnums(allocator: *Allocator, out: []registry.Declaration, root: *xml.Ele
 
         out[i] = .{
             .name = name,
-            .decl_type = .{.Enum = try parseEnumFields(allocator, enums)},
+            .decl_type = .{.enumeration = try parseEnumFields(allocator, enums)},
         };
         i += 1;
     }