diff --git a/lib/rbs_inline_data/parser.rb b/lib/rbs_inline_data/parser.rb
index 4221516..5d31696 100644
--- a/lib/rbs_inline_data/parser.rb
+++ b/lib/rbs_inline_data/parser.rb
@@ -7,7 +7,7 @@ class Parser < Prism::Visitor
     # @rbs skip
     TypedDefinition = Data.define(
       :class_name, #:: String
-      :fields #:: Array[TypedField]
+      :fields #:: Array[RbsInlineData::Parser::TypedField]
     )
     # @rbs skip
     TypedField = Data.define(
@@ -79,14 +79,14 @@ def define_data?(node)
     #:: (Prism::ConstantWriteNode) -> RbsInlineData::Parser::TypedDefinition?
     def extract_definition(node)
       source = node.slice
-      _, class_name, field_text = source.match(/\A([a-zA-Z]+) = Data\.define\(([\n\s\w\W]+)\)\z/).to_a
+      _, class_name, field_text = source.match(/\A([a-zA-Z0-9]+) ?= ?Data\.define\(([\n\s\w\W]+)\)\z/).to_a
       return nil if field_text.nil? || class_name.nil?
 
       class_name = "#{@surronding_class_or_module.join("::")}::#{class_name}"
 
       fields = field_text.split("\n").map(&:strip).reject(&:empty?).map do |str|
         case str
-        when /:(\w+),? #:: ([\w\[\]]+)/
+        when /:(\w+),? #:: ([\w\:\[\]]+)/
           [::Regexp.last_match(1), ::Regexp.last_match(2)]
         when /:(\w+),?/
           [::Regexp.last_match(1), "untyped"]
diff --git a/sig/generated/data/lib/rbs_inline_data/parser.rbs b/sig/generated/data/lib/rbs_inline_data/parser.rbs
index 8cb865c..e577d26 100644
--- a/sig/generated/data/lib/rbs_inline_data/parser.rbs
+++ b/sig/generated/data/lib/rbs_inline_data/parser.rbs
@@ -1,7 +1,7 @@
 class RbsInlineData::Parser::TypedDefinition
   extend Data::_DataClass
   attr_reader class_name: String
-  attr_reader fields: Array[TypedField]
+  attr_reader fields: Array[RbsInlineData::Parser::TypedField]
   def self.new: (*untyped) -> ::RbsInlineData::Parser::TypedDefinition
               | (**untyped) -> ::RbsInlineData::Parser::TypedDefinition
               | ...
diff --git a/test/rbs_inline_data/parser_test.rb b/test/rbs_inline_data/parser_test.rb
new file mode 100644
index 0000000..2b70a46
--- /dev/null
+++ b/test/rbs_inline_data/parser_test.rb
@@ -0,0 +1,109 @@
+require "test_helper"
+require "rbs_inline_data/parser"
+
+module RbsInlineData
+  class ParserTest < Minitest::Test
+    def parse_ruby(src)
+      Prism.parse(src)
+    end
+
+    def test_simple
+      definitions = Parser.parse(parse_ruby(<<~RUBY))
+        class Foo
+          Bar = Data.define(
+            :value, #:: String
+          )
+          Bar2=Data.define(
+            :value, #:: Integer
+          )
+        end
+      RUBY
+
+      assert_equal definitions[0], Parser::TypedDefinition.new(
+        class_name: "Foo::Bar",
+        fields: [
+          Parser::TypedField.new(field_name: "value", type: "String"),
+        ])
+      assert_equal definitions[1], Parser::TypedDefinition.new(
+        class_name: "Foo::Bar2",
+        fields: [
+          Parser::TypedField.new(field_name: "value", type: "Integer"),
+        ])
+    end
+
+    def test_multiple_definition
+      definitions = Parser.parse(parse_ruby(<<~RUBY))
+        class Foo
+          Bar = Data.define(
+            :string_value, #:: String
+          )
+          Bar2 = Data.define(
+            :string_value, #:: String
+          )
+        end
+      RUBY
+
+      assert_equal definitions[0], Parser::TypedDefinition.new(
+        class_name: "Foo::Bar",
+        fields: [
+          Parser::TypedField.new(field_name: "string_value", type: "String"),
+        ])
+      assert_equal definitions[1], Parser::TypedDefinition.new(
+        class_name: "Foo::Bar2",
+        fields: [
+          Parser::TypedField.new(field_name: "string_value", type: "String"),
+        ])
+    end
+
+    def test_untyped
+      definitions = Parser.parse(parse_ruby(<<~RUBY))
+        class Foo
+          Bar = Data.define(
+            :value #:: untyped
+          )
+          Bar2 = Data.define(
+            :value
+          )
+          Bar3 = Data.define(:value)
+        end
+      RUBY
+
+      assert_equal definitions[0], Parser::TypedDefinition.new(
+        class_name: "Foo::Bar",
+        fields: [
+          Parser::TypedField.new(field_name: "value", type: "untyped"),
+        ])
+      assert_equal definitions[1], Parser::TypedDefinition.new(
+        class_name: "Foo::Bar2",
+        fields: [
+          Parser::TypedField.new(field_name: "value", type: "untyped"),
+        ])
+      assert_equal definitions[2], Parser::TypedDefinition.new(
+        class_name: "Foo::Bar3",
+        fields: [
+          Parser::TypedField.new(field_name: "value", type: "untyped"),
+        ])
+    end
+
+    def test_nested_type
+      definitions = Parser.parse(parse_ruby(<<~RUBY))
+        class A
+          class B
+            class C; end
+            D = Data.define(
+              :x, #:: A::B::C
+              :y #:: Array[A::B::C]
+            )
+          end
+        end
+      RUBY
+
+      assert_equal definitions[0], Parser::TypedDefinition.new(
+        class_name: "A::B::D",
+        fields: [
+          Parser::TypedField.new(field_name: "x", type: "A::B::C"),
+          Parser::TypedField.new(field_name: "y", type: "Array[A::B::C]"),
+        ])
+    end
+  end
+end
diff --git a/test/test_rbs_inline_data.rb b/test/test_rbs_inline_data.rb
deleted file mode 100644
index 5dd4084..0000000
--- a/test/test_rbs_inline_data.rb
+++ /dev/null
@@ -1,13 +0,0 @@
-# frozen_string_literal: true
-
-require "test_helper"
-
-class TestRbsInlineData < Minitest::Test
-  def test_that_it_has_a_version_number
-    refute_nil ::RbsInlineData::VERSION
-  end
-
-  def test_it_does_something_useful
-    assert false
-  end
-end