diff --git a/lib/rbs/prototype/runtime.rb b/lib/rbs/prototype/runtime.rb
index 21cafd8ce..fd40ed893 100644
--- a/lib/rbs/prototype/runtime.rb
+++ b/lib/rbs/prototype/runtime.rb
@@ -395,7 +395,7 @@ def generate_class(mod)
         unless decl
           decl = AST::Declarations::Class.new(
             name: to_type_name(only_name(mod)),
-            type_params: [],
+            type_params: type_params(mod),
             super_class: generate_super_class(mod),
             members: [],
             annotations: [],
@@ -449,7 +449,7 @@ def generate_module(mod)
         unless decl
           decl = AST::Declarations::Module.new(
             name: to_type_name(only_name(mod)),
-            type_params: [],
+            type_params: type_params(mod),
             self_types: [],
             members: [],
             annotations: [],
@@ -504,7 +504,7 @@ def ensure_outer_module_declarations(mod)
             if outer_module.is_a?(Class)
               outer_decl = AST::Declarations::Class.new(
                 name: to_type_name(outer_module_name),
-                type_params: [],
+                type_params: type_params(outer_module),
                 super_class: generate_super_class(outer_module),
                 members: [],
                 annotations: [],
@@ -514,7 +514,7 @@ def ensure_outer_module_declarations(mod)
             else
               outer_decl = AST::Declarations::Module.new(
                 name: to_type_name(outer_module_name),
-                type_params: [],
+                type_params: type_params(outer_module),
                 self_types: [],
                 members: [],
                 annotations: [],
@@ -562,6 +562,15 @@ def type_args(type_name)
         end
       end
 
+      def type_params(mod)
+        type_name = to_type_name(const_name(mod), full_name: true)
+        if class_decl = env.class_decls[type_name.absolute!]
+          class_decl.type_params
+        else
+          []
+        end
+      end
+
       def block_from_ast_of(method)
         return nil if RUBY_VERSION < '3.1'
 
diff --git a/test/rbs/runtime_prototype_test.rb b/test/rbs/runtime_prototype_test.rb
index 25ca941a7..2b7bf6020 100644
--- a/test/rbs/runtime_prototype_test.rb
+++ b/test/rbs/runtime_prototype_test.rb
@@ -474,4 +474,48 @@ def test_nameerror_message
       end
     end
   end
+
+  class TestTypeParams
+    class TestTypeParams
+    end
+  end
+
+  def test_type_params
+    SignatureManager.new do |manager|
+      manager.files[Pathname("foo.rbs")] = <<~RBS
+        module RBS
+          class RuntimePrototypeTest < ::Test::Unit::TestCase
+            class TestTypeParams[unchecked out Elem]
+              class TestTypeParams
+              end
+            end
+          end
+        end
+      RBS
+
+      manager.build do |env|
+        p = Runtime.new(patterns: ["RBS::RuntimePrototypeTest::TestTypeParams"], env: env, merge: true)
+        assert_write p.decls, <<~RBS
+          module RBS
+            class RuntimePrototypeTest < ::Test::Unit::TestCase
+              class TestTypeParams[unchecked out Elem]
+              end
+            end
+          end
+        RBS
+
+        p = Runtime.new(patterns: ["RBS::RuntimePrototypeTest::TestTypeParams::TestTypeParams"], env: env, merge: true)
+        assert_write p.decls, <<~RBS
+          module RBS
+            class RuntimePrototypeTest < ::Test::Unit::TestCase
+              class TestTypeParams[unchecked out Elem]
+                class TestTypeParams
+                end
+              end
+            end
+          end
+        RBS
+      end
+    end
+  end
 end