diff --git a/lib/rbs/definition_builder.rb b/lib/rbs/definition_builder.rb
index 44f572141..4aa7f845e 100644
--- a/lib/rbs/definition_builder.rb
+++ b/lib/rbs/definition_builder.rb
@@ -753,12 +753,14 @@ def expand_alias(type_name)
     end
 
     def expand_alias1(type_name)
+      type_name = env.normalize_type_name(type_name)
       entry = env.type_alias_decls[type_name] or raise "Unknown alias name: #{type_name}"
       as = entry.decl.type_params.each.map { Types::Bases::Any.new(location: nil) }
       expand_alias2(type_name, as)
     end
 
     def expand_alias2(type_name, args)
+      type_name = env.normalize_type_name(type_name)
       entry = env.type_alias_decls[type_name] or raise "Unknown alias name: #{type_name}"
 
       ensure_namespace!(type_name.namespace, location: entry.decl.location)
@@ -811,9 +813,8 @@ def validate_type_presence(type)
     end
 
     def validate_type_name(name, location)
-      name = name.absolute!
-
-      return if env.type_name?(name)
+      name = name.absolute! unless name.absolute?
+      return if env.type_name?(env.normalize_type_name(name))
 
       raise NoTypeFoundError.new(type_name: name, location: location)
     end
diff --git a/lib/rbs/environment.rb b/lib/rbs/environment.rb
index 691f75c56..32c865cdb 100644
--- a/lib/rbs/environment.rb
+++ b/lib/rbs/environment.rb
@@ -275,53 +275,96 @@ def constant_entry(type_name)
       class_entry(type_name) || module_entry(type_name) || constant_decls[type_name]
     end
 
+    def normalize_type_name?(name)
+      if name.class?
+        normalize_module_name?(name)
+      else
+        unless name.namespace.empty?
+          parent = name.namespace.to_type_name
+          parent = normalize_module_name?(parent)
+          return parent unless parent
+
+          TypeName.new(namespace: parent.to_namespace, name: name.name)
+        else
+          name
+        end
+      end
+    end
+
+    def normalize_type_name!(name)
+      result = normalize_type_name?(name)
+
+      case result
+      when TypeName
+        result
+      when false
+        raise "Type name `#{name}` cannot be normalized because it's a cyclic definition"
+      when nil
+        raise "Type name `#{name}` cannot be normalized because of unknown type name in the path"
+      end
+    end
+
+    def normalized_type_name?(type_name)
+      case
+      when type_name.interface?
+        interface_decls.key?(type_name)
+      when type_name.class?
+        class_decls.key?(type_name)
+      when type_name.alias?
+        type_alias_decls.key?(type_name)
+      else
+        false
+      end
+    end
+
+    def normalized_type_name!(name)
+      normalized_type_name?(name) or raise "Normalized type name is expected but given `#{name}`, which is normalized to `#{normalize_type_name?(name)}`"
+      name
+    end
+
+    def normalize_type_name(name)
+      normalize_type_name?(name) || name
+    end
+
     def normalize_module_name(name)
       normalize_module_name?(name) or name
     end
 
     def normalize_module_name?(name)
       raise "Class/module name is expected: #{name}" unless name.class?
-      name = name.absolute! if name.relative!
+      name = name.absolute! unless name.absolute?
 
       if @normalize_module_name_cache.key?(name)
         return @normalize_module_name_cache[name]
       end
 
+      unless name.namespace.empty?
+        parent = name.namespace.to_type_name
+        if normalized_parent = normalize_module_name?(parent)
+          type_name = TypeName.new(namespace: normalized_parent.to_namespace, name: name.name)
+        else
+          @normalize_module_name_cache[name] = nil
+          return
+        end
+      else
+        type_name = name
+      end
+
       @normalize_module_name_cache[name] = false
 
-      entry = constant_entry(name)
-      case entry
-      when ClassEntry, ModuleEntry
-        @normalize_module_name_cache[name] = entry.name
-        entry.name
+      entry = constant_entry(type_name)
 
-      when ClassAliasEntry, ModuleAliasEntry
-        old_name = entry.decl.old_name
-        if old_name.namespace.empty?
-          @normalize_module_name_cache[name] = normalize_module_name?(old_name)
+      normalized_type_name =
+        case entry
+        when ClassEntry, ModuleEntry
+          type_name
+        when ClassAliasEntry, ModuleAliasEntry
+          normalize_module_name?(entry.decl.old_name)
         else
-          parent = old_name.namespace.to_type_name
-
-          if normalized_parent = normalize_module_name?(parent)
-            @normalize_module_name_cache[name] =
-              if normalized_parent == parent
-                normalize_module_name?(old_name)
-              else
-                normalize_module_name?(
-                  TypeName.new(name: old_name.name, namespace: normalized_parent.to_namespace)
-                )
-              end
-          else
-            @normalize_module_name_cache[name] = nil
-          end
+          nil
         end
 
-      when ConstantEntry
-        raise "#{name} is a constant name"
-
-      else
-        @normalize_module_name_cache[name] = nil
-      end
+      @normalize_module_name_cache[name] = normalized_type_name
     end
 
     def insert_decl(decl, outer:, namespace:)
diff --git a/lib/rbs/errors.rb b/lib/rbs/errors.rb
index dfdc95732..84cba18cc 100644
--- a/lib/rbs/errors.rb
+++ b/lib/rbs/errors.rb
@@ -192,7 +192,8 @@ def location
     end
 
     def self.check!(super_decl, env:)
-      return if env.class_decl?(super_decl.name) || env.class_alias?(super_decl.name)
+      super_name = env.normalize_type_name(super_decl.name)
+      return if env.class_decl?(super_name) || env.class_alias?(super_name)
 
       raise new(super_decl)
     end
@@ -212,9 +213,8 @@ def initialize(type_name:, location:)
     end
 
     def self.check!(self_type, env:)
-      type_name = self_type.name
-
-      (env.module_name?(type_name) || env.interface_name?(type_name)) or raise new(type_name: type_name, location: self_type.location)
+      self_name = env.normalize_type_name(self_type.name)
+      (env.module_name?(self_name) || env.interface_name?(self_name)) or raise new(type_name: self_type.name, location: self_type.location)
     end
   end
 
diff --git a/lib/rbs/resolver/type_name_resolver.rb b/lib/rbs/resolver/type_name_resolver.rb
index 5e3a348ab..8b71f4b2e 100644
--- a/lib/rbs/resolver/type_name_resolver.rb
+++ b/lib/rbs/resolver/type_name_resolver.rb
@@ -5,10 +5,12 @@ module Resolver
     class TypeNameResolver
       attr_reader :all_names
       attr_reader :cache
+      attr_reader :env
 
       def initialize(env)
         @all_names = Set[]
         @cache = {}
+        @env = env
 
         all_names.merge(env.class_decls.keys)
         all_names.merge(env.interface_decls.keys)
@@ -35,7 +37,10 @@ def resolve(type_name, context:)
 
           if head
             if tail
-              has_name?(tail.with_prefix(head.to_namespace))
+              absolute_name = tail.with_prefix(head.to_namespace)
+              if env.normalize_type_name?(absolute_name)
+                absolute_name
+              end
             else
               head
             end
diff --git a/lib/rbs/type_alias_dependency.rb b/lib/rbs/type_alias_dependency.rb
index 0e1ef6175..7930c2165 100644
--- a/lib/rbs/type_alias_dependency.rb
+++ b/lib/rbs/type_alias_dependency.rb
@@ -20,7 +20,7 @@ def circular_definition?(alias_name)
       # Construct transitive closure, if not constructed already
       transitive_closure() unless @dependencies
 
-      # Check for recursive type alias
+      alias_name = env.normalize_type_name!(alias_name)
       @dependencies[alias_name][alias_name]
     end
 
@@ -49,6 +49,16 @@ def transitive_closure
       end
     end
 
+    def direct_dependencies_of(name)
+      name = env.normalize_type_name!(name)
+      @direct_dependencies[name]
+    end
+
+    def dependencies_of(name)
+      name = env.normalize_type_name!(name)
+      @dependencies[name].each_key.to_set
+    end
+
     private
 
     # Constructs directed graph recursively
@@ -61,7 +71,7 @@ def direct_dependency(type, result = Set[])
         end
       when RBS::Types::Alias
         # Append type name if the type is an alias
-        result << type.name
+        result << env.normalize_type_name(type.name)
       end
 
       result
diff --git a/lib/rbs/type_alias_regularity.rb b/lib/rbs/type_alias_regularity.rb
index a6af16bc8..a891432ec 100644
--- a/lib/rbs/type_alias_regularity.rb
+++ b/lib/rbs/type_alias_regularity.rb
@@ -37,10 +37,12 @@ def validate
     end
 
     def validate_alias_type(alias_type, names, types)
-      if names.include?(alias_type.name)
-        if ex_type = types[alias_type.name]
+      alias_name = env.normalize_type_name?(alias_type.name) or return
+
+      if names.include?(alias_name)
+        if ex_type = types[alias_name]
           unless compatible_args?(ex_type.args, alias_type.args)
-            diagnostics[alias_type.name] ||=
+            diagnostics[alias_name] ||=
               Diagnostic.new(type_name: alias_type.name, nonregular_type: alias_type)
           end
 
@@ -49,7 +51,7 @@ def validate_alias_type(alias_type, names, types)
           types[alias_type.name] = alias_type
         end
 
-        expanded = builder.expand_alias2(alias_type.name, alias_type.args)
+        expanded = builder.expand_alias2(alias_name, alias_type.args)
         each_alias_type(expanded) do |at|
           validate_alias_type(at, names, types)
         end
@@ -75,22 +77,27 @@ def compatible_args?(args1, args2)
     end
 
     def nonregular?(type_name)
-      diagnostics[type_name]
+      diagnostics[env.normalize_type_name!(type_name)]
     end
 
     def each_mutual_alias_defs(&block)
-      # @type var each_node: TSort::_EachNode[TypeName]
-      each_node = __skip__ = -> (&block) do
+      # @type var each_node: ^() { (TypeName) -> void } -> void
+      each_node = -> (&block) do
         env.type_alias_decls.each_value do |decl|
-          block[decl.name]
+          if normalized = env.normalize_type_name?(decl.name)
+            block[normalized]
+          end
         end
       end
-      # @type var each_child: TSort::_EachChild[TypeName]
-      each_child = __skip__ = -> (name, &block) do
+
+      # @type var each_child: ^(TypeName) { (TypeName) -> void } -> void
+      each_child = -> (name, &block) do
         if env.type_alias_decls.key?(name)
           type = builder.expand_alias1(name)
           each_alias_type(type) do |ty|
-            block[ty.name]
+            if normalized = env.normalize_type_name?(ty.name)
+              block[normalized]
+            end
           end
         end
       end
diff --git a/lib/rbs/validator.rb b/lib/rbs/validator.rb
index f17af0fa9..833836ae8 100644
--- a/lib/rbs/validator.rb
+++ b/lib/rbs/validator.rb
@@ -12,9 +12,9 @@ def initialize(env:, resolver:)
       @definition_builder = DefinitionBuilder.new(env: env)
     end
 
-    def absolute_type(type, context:)
+    def absolute_type(type, context:, &block)
       type.map_type_name do |type_name, _, type|
-        resolver.resolve(type_name, context: context) || yield(type)
+        resolver.resolve(type_name, context: context) || (block ? yield(type) : type_name)
       end
     end
 
@@ -22,33 +22,34 @@ def absolute_type(type, context:)
     def validate_type(type, context:)
       case type
       when Types::ClassInstance, Types::Interface, Types::Alias
-        # @type var type: Types::ClassInstance | Types::Interface | Types::Alias
-        if type.name.namespace.relative?
-          type = _ = absolute_type(type, context: context) do |_|
-            NoTypeFoundError.check!(type.name.absolute!, env: env, location: type.location)
-          end
-        end
+        type = absolute_type(type, context: context) #: Types::ClassInstance | Types::Interface | Types::Alias
 
         definition_builder.validate_type_name(type.name, type.location)
 
-        type_params = case type
-                      when Types::ClassInstance
-                        entry = env.normalized_module_class_entry(type.name) or raise
-                        entry.type_params
-                      when Types::Interface
-                        env.interface_decls[type.name].decl.type_params
-                      when Types::Alias
-                        env.type_alias_decls[type.name].decl.type_params
-                      end
-
-        InvalidTypeApplicationError.check!(
-          type_name: type.name,
-          args: type.args,
-          params: type_params.each.map(&:name),
-          location: type.location
-        )
+        normalized_type_name = env.normalize_type_name?(type.name)
+
+        if normalized_type_name
+          type_params =
+            case type
+            when Types::ClassInstance
+              entry = env.class_decls[normalized_type_name] or raise
+              entry.type_params
+            when Types::Interface
+              env.interface_decls[normalized_type_name].decl.type_params
+            when Types::Alias
+              env.type_alias_decls[normalized_type_name].decl.type_params
+            end
+
+          InvalidTypeApplicationError.check!(
+            type_name: type.name,
+            args: type.args,
+            params: type_params.each.map(&:name),
+            location: type.location
+          )
+        end
 
       when Types::ClassSingleton
+        type = absolute_type(type, context: context) #: Types::ClassSingleton
         definition_builder.validate_type_presence(type)
       end
 
@@ -115,14 +116,14 @@ def validate_method_definition(method_def, type_name:)
     end
 
     def validate_type_params(params, type_name: , method_name: nil, location:)
-      # @type var each_node: TSort::_EachNode[Symbol]
-      each_node = __skip__ = -> (&block) do
+      # @type var each_node: ^() { (Symbol) -> void } -> void
+      each_node = -> (&block) do
         params.each do |param|
           block[param.name]
         end
       end
-      # @type var each_child: TSort::_EachChild[Symbol]
-      each_child = __skip__ = -> (name, &block) do
+      # @type var each_child: ^(Symbol) { (Symbol) -> void } -> void
+      each_child = -> (name, &block) do
         if param = params.find {|p| p.name == name }
           if b = param.upper_bound
             b.free_variables.each do |tv|
diff --git a/lib/rbs/variance_calculator.rb b/lib/rbs/variance_calculator.rb
index 2a42c5b14..ba033ea84 100644
--- a/lib/rbs/variance_calculator.rb
+++ b/lib/rbs/variance_calculator.rb
@@ -108,8 +108,11 @@ def in_inherit(name:, args:, variables:)
     end
 
     def in_type_alias(name:)
+      env.normalized_type_name!(name)
+
       decl = env.type_alias_decls[name].decl or raise
       variables = decl.type_params.each.map(&:name)
+
       Result.new(variables: variables).tap do |result|
         type(decl.type, result: result, context: :covariant)
       end
@@ -129,30 +132,30 @@ def type(type, result:, context:)
           end
         end
       when Types::ClassInstance, Types::Interface, Types::Alias
-        NoTypeFoundError.check!(type.name,
-                                env: env,
-                                location: type.location)
-
-        type_params = case type
-                      when Types::ClassInstance
-                        env.class_decls[env.normalize_module_name(type.name)].type_params
-                      when Types::Interface
-                        env.interface_decls[type.name].decl.type_params
-                      when Types::Alias
-                        env.type_alias_decls[type.name].decl.type_params
-                      end
-
-        type.args.each.with_index do |ty, i|
-          if var = type_params[i]
-            case var.variance
-            when :invariant
-              type(ty, result: result, context: :invariant)
-            when :covariant
-              type(ty, result: result, context: context)
-            when :contravariant
-              type(ty, result: result, context: negate(context))
+        if type_name = env.normalize_type_name?(type.name)
+          type_params = case type
+                        when Types::ClassInstance
+                          env.class_decls[type_name].type_params
+                        when Types::Interface
+                          env.interface_decls[type_name].decl.type_params
+                        when Types::Alias
+                          env.type_alias_decls[type_name].decl.type_params
+                        end
+
+          type.args.each.with_index do |ty, i|
+            if var = type_params[i]
+              case var.variance
+              when :invariant
+                type(ty, result: result, context: :invariant)
+              when :covariant
+                type(ty, result: result, context: context)
+              when :contravariant
+                type(ty, result: result, context: negate(context))
+              end
             end
           end
+        else
+          raise NoTypeFoundError.new(type_name: type.name, location: type.location)
         end
       when Types::Proc
         function(type.type, result: result, context: context)
diff --git a/sig/definition_builder.rbs b/sig/definition_builder.rbs
index e2b6f3e53..cc177b9e0 100644
--- a/sig/definition_builder.rbs
+++ b/sig/definition_builder.rbs
@@ -71,12 +71,16 @@ module RBS
     # Assumes the type names are already resolved.
     # Raises NoTypeFoundError in case of failure.
     #
+    # Normalizes type names in the given type automatically.
+    #
     def validate_type_presence: (Types::t) -> void
 
     # Validates presence of an absolute type name
     #
     # Raises NoTypeFoundError in case of error.
     #
+    # Normalizes the given type name automatically.
+    #
     def validate_type_name: (TypeName, Location[untyped, untyped]?) -> void
 
     # Returns a new DefinitionBuilder with updated Environment, AncestorBuilder, and exceptions
diff --git a/sig/environment.rbs b/sig/environment.rbs
index 66ec574ef..cb8555c82 100644
--- a/sig/environment.rbs
+++ b/sig/environment.rbs
@@ -224,6 +224,33 @@ module RBS
     #
     def normalize_module_name: (TypeName) -> TypeName
 
+    # Returns a normalized module/class name or a type name with a normalized namespace
+    #
+    # * Calls `#absolute!` for relative module names
+    # * Returns `nil` if the typename cannot be found
+    # * Returns `false` if the name is cyclic
+    #
+    def normalize_type_name?: (TypeName) -> (TypeName | nil | false)
+
+    # Normalize the type name or raises an error
+    # 
+    def normalize_type_name!: (TypeName) -> TypeName
+
+    # Returns a normalized module/class name or a type name with a normalized namespace
+    #
+    # * Calls `#absolute!` for relative module names
+    # * Returns the typename itself if the name cannot be normalized
+    #
+    def normalize_type_name: (TypeName) -> TypeName
+
+    # Returns `true` if given type name is normalized
+    #
+    def normalized_type_name?: (TypeName) -> bool
+
+    # Returns the given type name if it's normalized, or raises
+    #
+    def normalized_type_name!: (TypeName) -> TypeName
+
     # Runs generics type params validation over each class definitions
     def validate_type_params: () -> void
 
diff --git a/sig/errors.rbs b/sig/errors.rbs
index 6e430c316..ed8fc9a89 100644
--- a/sig/errors.rbs
+++ b/sig/errors.rbs
@@ -82,7 +82,7 @@ module RBS
 
   class NoTypeFoundError < DefinitionError
     include DetailedMessageable
-    
+
     attr_reader type_name: TypeName
     attr_reader location: Location[untyped, untyped]?
 
@@ -108,6 +108,8 @@ module RBS
 
     def initialize: (type_name: TypeName, location: Location[untyped, untyped]?) -> void
 
+    # The type name in `self` is automatically normalized
+    #
     def self.check!: (AST::Declarations::Module::Self, env: Environment) -> void
   end
 
@@ -177,7 +179,7 @@ module RBS
     def type_name: () -> TypeName
 
     def qualified_method_name: () -> String
-                             
+
     def location: () -> AST::Members::Mixin::loc?
   end
 
@@ -212,7 +214,7 @@ module RBS
     attr_reader members: Array[AST::Members::MethodDefinition]
 
     def initialize: (type_name: TypeName, method_name: Symbol, kind: :instance | :singleton, members: Array[AST::Members::MethodDefinition]) -> void
-                  
+
     def location: () -> AST::Members::MethodDefinition::loc?
   end
 
@@ -284,6 +286,10 @@ module RBS
 
     def location: () -> Location[untyped, untyped]?
 
+    # Confirms if `super` inherits specifies a class
+    #
+    # Automatically normalize the name of super.
+    #
     def self.check!: (AST::Declarations::Class::Super, env: Environment) -> void
   end
 
@@ -352,7 +358,7 @@ module RBS
     attr_reader alias_entry: Environment::ModuleAliasEntry | Environment::ClassAliasEntry
 
     def initialize: (Environment::ModuleAliasEntry | Environment::ClassAliasEntry) -> void
-                  
+
     def location: () -> AST::Declarations::AliasDecl::loc?
   end
 end
diff --git a/sig/resolver/type_name_resolver.rbs b/sig/resolver/type_name_resolver.rbs
index 650c1914d..96d156ea9 100644
--- a/sig/resolver/type_name_resolver.rbs
+++ b/sig/resolver/type_name_resolver.rbs
@@ -17,6 +17,8 @@ module RBS
 
       private
 
+      attr_reader env: Environment
+
       attr_reader all_names: Set[TypeName]
 
       attr_reader cache: Hash[query, TypeName?]
diff --git a/sig/type_alias_dependency.rbs b/sig/type_alias_dependency.rbs
index a8cf3ec5b..45595c3be 100644
--- a/sig/type_alias_dependency.rbs
+++ b/sig/type_alias_dependency.rbs
@@ -1,14 +1,45 @@
 module RBS
+  # TypeAliasDependency calculates the dependnecies between type aliases
+  #
+  # The dependencies are normalized automatically.
+  #
   class TypeAliasDependency
     attr_reader env: Environment
 
+    # A hash table from type alias name to it's direct dependencies
+    #
+    # The source type name and dependencies are normalized.
+    #
     attr_reader direct_dependencies: Hash[TypeName, Set[TypeName]]
+
+    # A hash table from type alias name to a hash name with keys of transitive dependnecies
+    #
+    # The source type name and dependencies are normalized.
+    #
     attr_reader dependencies: Hash[TypeName, Hash[TypeName, bool]]
 
     def initialize: (env: Environment) -> void
 
+    # Returns `true` if given type alias is circular
+    #
+    # Normalized given type name automatically.
+    #
     def circular_definition?: (TypeName alias_name) -> bool
 
+    # Returns the set of direct dependencies from the given type name
+    #
+    # Given type name will be normalized automatically.
+    # Returns normalized type names.
+    #
+    def direct_dependencies_of: (TypeName) -> Set[TypeName]
+
+    # Returns the set of dependencies from the given type name
+    #
+    # Given type name will be normalized automatically.
+    # Returns normalized type names.
+    #
+    def dependencies_of: (TypeName) -> Set[TypeName]
+
     def build_dependencies: () -> void
 
     def transitive_closure: () -> void
diff --git a/sig/type_alias_regularity.rbs b/sig/type_alias_regularity.rbs
index ab4e0f748..26b759e56 100644
--- a/sig/type_alias_regularity.rbs
+++ b/sig/type_alias_regularity.rbs
@@ -36,6 +36,9 @@ module RBS
 
     attr_reader builder: DefinitionBuilder
 
+    # Diagnostics of each type aliases.
+    # The type names are normalized.
+    #
     attr_reader diagnostics: Hash[TypeName, Diagnostic]
 
     # `Diagnostic` represents an non-regular type alias declaration error.
@@ -70,6 +73,8 @@ module RBS
     # Returns `Diagnostic` instance if the alias type is nonregular.
     # Regurns `nil` if the alias type is regular.
     #
+    # Normalizes the given type name automatically.
+    #
     def nonregular?: (TypeName) -> Diagnostic?
 
     def validate: () -> void
@@ -87,6 +92,7 @@ module RBS
 
     def each_alias_type: (Types::t) { (Types::Alias) -> void } -> void
 
+    # Yields set of normalized type names
     def each_mutual_alias_defs: () { (Set[TypeName]) -> void } -> void
   end
 end
diff --git a/sig/validator.rbs b/sig/validator.rbs
index 42813054f..358a963d4 100644
--- a/sig/validator.rbs
+++ b/sig/validator.rbs
@@ -46,7 +46,7 @@ module RBS
     #
     # - The right hand side can be normalized
     # - No mixing alias declaration between class and modules
-    # 
+    #
     def validate_class_alias: (entry: Environment::ClassAliasEntry | Environment::ModuleAliasEntry) -> void
 
     private
@@ -54,6 +54,6 @@ module RBS
     # Resolves relative type names to absolute type names in given context.
     # Yields the type when the type name resolution using `#resolver` fails.
     #
-    def absolute_type: (Types::t, context: Resolver::context) { (Types::t) -> TypeName } -> Types::t
+    def absolute_type: (Types::t, context: Resolver::context) ?{ (Types::t) -> TypeName } -> Types::t
   end
 end
diff --git a/sig/variance_calculator.rbs b/sig/variance_calculator.rbs
index a6fe009fc..3294fd538 100644
--- a/sig/variance_calculator.rbs
+++ b/sig/variance_calculator.rbs
@@ -72,6 +72,8 @@ module RBS
 
     def in_inherit: (name: TypeName, args: Array[Types::t], variables: Array[Symbol]) -> Result
 
+    # The type name must be normalized
+    # 
     def in_type_alias: (name: TypeName) -> Result
 
     private
diff --git a/test/rbs/definition_builder_test.rb b/test/rbs/definition_builder_test.rb
index b6f42ae7d..465fb8dfc 100644
--- a/test/rbs/definition_builder_test.rb
+++ b/test/rbs/definition_builder_test.rb
@@ -2593,4 +2593,74 @@ def self.f: () -> String | ...
       end
     end
   end
+
+  def test_module_alias__superclass
+    SignatureManager.new do |manager|
+      manager.add_file("foo.rbs", <<-EOF)
+module Foo
+  class Bar
+  end
+end
+
+module Baz = Foo
+
+class Hoge < Baz::Bar
+end
+      EOF
+
+      manager.build do |env|
+        root = nil
+
+        builder = DefinitionBuilder.new(env: env)
+
+        builder.build_instance(type_name("::Hoge"))
+        builder.build_singleton(type_name("::Hoge"))
+      end
+    end
+  end
+
+  def test_module_alias__mixin
+    SignatureManager.new do |manager|
+      manager.add_file("foo.rbs", <<-EOF)
+module Foo
+end
+
+module Bar = Foo
+
+class Baz
+  include Bar
+  include Bar
+end
+      EOF
+
+      manager.build do |env|
+        root = nil
+
+        builder = DefinitionBuilder.new(env: env)
+
+        builder.build_instance(type_name("::Baz"))
+        builder.build_singleton(type_name("::Baz"))
+      end
+    end
+  end
+
+  def test_module_alias__module_self
+    SignatureManager.new do |manager|
+      manager.add_file("foo.rbs", <<-EOF)
+class Foo = Integer
+
+module Bar : Foo
+end
+      EOF
+
+      manager.build do |env|
+        root = nil
+
+        builder = DefinitionBuilder.new(env: env)
+
+        builder.build_instance(type_name("::Bar"))
+        builder.build_singleton(type_name("::Bar"))
+      end
+    end
+  end
 end
diff --git a/test/rbs/resolver/type_name_resolver_test.rb b/test/rbs/resolver/type_name_resolver_test.rb
index 40d47aea6..c7bac502f 100644
--- a/test/rbs/resolver/type_name_resolver_test.rb
+++ b/test/rbs/resolver/type_name_resolver_test.rb
@@ -128,4 +128,24 @@ class MyObject
       end
     end
   end
+
+  def test_module_alias
+    SignatureManager.new do |manager|
+      manager.files[Pathname("foo.rbs")] = <<EOF
+class MyObject
+  type name2 = ::Symbol
+end
+
+class Alias = MyObject
+
+type foo = Alias::name2
+EOF
+      manager.build do |env|
+        resolver = Resolver::TypeNameResolver.new(env)
+
+        assert_equal type_name("::Alias::name2"),
+                     resolver.resolve(type_name("Alias::name2"), context: nil)
+      end
+    end
+  end
 end
diff --git a/test/rbs/type_alias_dependency_test.rb b/test/rbs/type_alias_dependency_test.rb
new file mode 100644
index 000000000..aebc5dde7
--- /dev/null
+++ b/test/rbs/type_alias_dependency_test.rb
@@ -0,0 +1,63 @@
+require "test_helper"
+
+class TypeAliasDependencyTest < Test::Unit::TestCase
+  include TestHelper
+
+  include RBS
+
+  def test_dependency
+    SignatureManager.new do |manager|
+      manager.add_file("foo.rbs", <<-EOF)
+type foo = Integer
+
+type bar = foo | String
+
+type baz = bar | foo | Integer
+      EOF
+
+      manager.build do |env|
+        alias_dependency = TypeAliasDependency.new(env: env)
+        alias_dependency.transitive_closure()
+
+        assert_equal Set[], alias_dependency.direct_dependencies[TypeName("::foo")]
+        assert_equal Set[TypeName("::foo")], alias_dependency.direct_dependencies[TypeName("::bar")]
+        assert_equal Set[TypeName("::foo"), TypeName("::bar")], alias_dependency.direct_dependencies[TypeName("::baz")]
+      end
+    end
+  end
+
+  def test_dependency__module_alias
+    SignatureManager.new do |manager|
+      manager.add_file("foo.rbs", <<-EOF)
+module Foo
+  type foo = Integer
+
+  type bar = Bar::foo
+end
+
+module Bar = Foo
+
+type Foo::baz = Bar::bar | String
+      EOF
+
+      manager.build do |env|
+        alias_dependency = TypeAliasDependency.new(env: env)
+        alias_dependency.transitive_closure()
+
+        assert_equal Set[], alias_dependency.direct_dependencies_of(TypeName("::Foo::foo"))
+        assert_equal Set[], alias_dependency.direct_dependencies_of(TypeName("::Bar::foo"))
+        assert_equal Set[TypeName("::Foo::foo")], alias_dependency.direct_dependencies_of(TypeName("::Foo::bar"))
+        assert_equal Set[TypeName("::Foo::foo")], alias_dependency.direct_dependencies_of(TypeName("::Bar::bar"))
+        assert_equal Set[TypeName("::Foo::bar")], alias_dependency.direct_dependencies_of(TypeName("::Foo::baz"))
+        assert_equal Set[TypeName("::Foo::bar")], alias_dependency.direct_dependencies_of(TypeName("::Bar::baz"))
+
+        assert_equal Set[], alias_dependency.dependencies_of(TypeName("::Foo::foo"))
+        assert_equal Set[], alias_dependency.dependencies_of(TypeName("::Bar::foo"))
+        assert_equal Set[TypeName("::Foo::foo")], alias_dependency.dependencies_of(TypeName("::Foo::bar"))
+        assert_equal Set[TypeName("::Foo::foo")], alias_dependency.dependencies_of(TypeName("::Bar::bar"))
+        assert_equal Set[TypeName("::Foo::foo"), TypeName("::Foo::bar")], alias_dependency.dependencies_of(TypeName("::Foo::baz"))
+        assert_equal Set[TypeName("::Foo::foo"), TypeName("::Foo::bar")], alias_dependency.dependencies_of(TypeName("::Bar::baz"))
+      end
+    end
+  end
+end
diff --git a/test/rbs/type_alias_regulartiry_test.rb b/test/rbs/type_alias_regulartiry_test.rb
index 241ad844b..1fc0f1c81 100644
--- a/test/rbs/type_alias_regulartiry_test.rb
+++ b/test/rbs/type_alias_regulartiry_test.rb
@@ -52,4 +52,40 @@ def test_validate_mutual
       end
     end
   end
+
+  def test_validate__module_aliases
+    SignatureManager.new do |manager|
+      manager.add_file("foo.rbs", <<-EOF)
+module Foo
+end
+
+module Bar = Foo
+
+type Foo::foo = Integer
+
+type Foo::bar[T] = [Foo::bar[T], T, Bar::bar[T]]
+                 | nil
+
+type Foo::baz[T] = Bar::baz[Foo::bar[T]]
+                 | nil
+      EOF
+
+      manager.build do |env|
+        validator = TypeAliasRegularity.validate(env: env)
+
+        refute_operator validator, :nonregular?, TypeName("::Foo::foo")
+        refute_operator validator, :nonregular?, TypeName("::Bar::foo")
+        refute_operator validator, :nonregular?, TypeName("::Foo::bar")
+        refute_operator validator, :nonregular?, TypeName("::Bar::bar")
+
+        assert_operator validator, :nonregular?, TypeName("::Foo::baz")
+        assert_operator validator, :nonregular?, TypeName("::Bar::baz")
+
+        assert_equal(
+          parse_type("::Bar::baz[::Foo::bar[T]]", variables: [:T]),
+          validator.nonregular?(TypeName("::Foo::baz")).nonregular_type
+        )
+      end
+    end
+  end
 end
diff --git a/test/rbs/variance_calculator_test.rb b/test/rbs/variance_calculator_test.rb
index 87fbde9fb..e284af2cb 100644
--- a/test/rbs/variance_calculator_test.rb
+++ b/test/rbs/variance_calculator_test.rb
@@ -118,4 +118,26 @@ def test_result
     assert result.compatible?(:B, with_annotation: :invariant)
     assert result.compatible?(:C, with_annotation: :invariant)
   end
+
+  def test_type_alias
+    SignatureManager.new do |manager|
+      manager.files[Pathname("foo.rbs")] = <<EOF
+module Foo
+end
+
+module Bar = Foo
+
+type Foo::foo[out T] = String?
+
+type Foo::bar[in T] = ^(Bar::foo[T]) -> Integer
+EOF
+      manager.build do |env|
+        builder = DefinitionBuilder.new(env: env)
+        calculator = VarianceCalculator.new(builder: builder)
+
+        calculator.in_type_alias(name: TypeName("::Foo::foo"))
+        calculator.in_type_alias(name: TypeName("::Foo::bar"))
+      end
+    end
+  end
 end
diff --git a/test/validator_test.rb b/test/validator_test.rb
index 50e872673..fd8e2acaf 100644
--- a/test/validator_test.rb
+++ b/test/validator_test.rb
@@ -276,4 +276,95 @@ class Baz = Baz
       end
     end
   end
+
+  def test_validate_type__presence__module_alias_instance
+    SignatureManager.new do |manager|
+      manager.add_file("foo.rbs", <<-EOF)
+module Foo
+end
+
+module Bar = Foo
+
+class Foo::Baz = Integer
+
+type foo = Bar::Baz
+      EOF
+
+      manager.build do |env|
+        root = nil
+
+        resolver = RBS::Resolver::TypeNameResolver.new(env)
+        validator = RBS::Validator.new(env: env, resolver: resolver)
+
+        validator.validate_type(parse_type("Bar::Baz"), context: root)
+      end
+    end
+  end
+
+  def test_validate_type__presence__module_alias_singleton
+    SignatureManager.new do |manager|
+      manager.add_file("foo.rbs", <<-EOF)
+module Foo
+end
+
+module Bar = Foo
+
+class Foo::Baz = Integer
+      EOF
+
+      manager.build do |env|
+        root = nil
+
+        resolver = RBS::Resolver::TypeNameResolver.new(env)
+        validator = RBS::Validator.new(env: env, resolver: resolver)
+
+        validator.validate_type(parse_type("singleton(Bar::Baz)"), context: root)
+      end
+    end
+  end
+
+  def test_validate_type__ality_module_alias
+    SignatureManager.new do |manager|
+      manager.add_file("foo.rbs", <<-EOF)
+module Foo
+  type list[T] = nil | [T, list[T]]
+end
+
+module Bar = Foo
+      EOF
+
+      manager.build do |env|
+        root = nil
+
+        resolver = RBS::Resolver::TypeNameResolver.new(env)
+        validator = RBS::Validator.new(env: env, resolver: resolver)
+
+        validator.validate_type(parse_type("Bar::list[Bar]"), context: root)
+      end
+    end
+  end
+
+  def test_validate_type_alias__1
+    SignatureManager.new do |manager|
+      manager.add_file("foo.rbs", <<-EOF)
+module Foo
+end
+
+module Bar = Foo
+
+class Baz = Numeric
+
+type Foo::list[T < Baz] = nil | [T, Bar::list[T]]
+      EOF
+
+      manager.build do |env|
+        root = nil
+
+        resolver = RBS::Resolver::TypeNameResolver.new(env)
+        validator = RBS::Validator.new(env: env, resolver: resolver)
+
+        validator.validate_type_alias(entry: env.type_alias_decls[TypeName("::Foo::list")])
+      end
+    end
+  end
 end