diff --git a/test/ruby/test_array.rb b/test/ruby/test_array.rb
index 436906ae32..feeccd4e0a 100644
--- a/test/ruby/test_array.rb
+++ b/test/ruby/test_array.rb
@@ -1821,7 +1821,7 @@ class TestArray < Test::Unit::TestCase
     assert_equal(b, @cls[0, 1, 2, 3, 4][1, 4].permutation.to_a, bug3708)
 
     bug9932 = '[ruby-core:63103] [Bug #9932]'
-    assert_separately([], <<-"end;") #    do
+    assert_separately([], <<-"end;", timeout: 30) #    do
       assert_nothing_raised(SystemStackError, "#{bug9932}") do
         assert_equal(:ok, Array.new(100_000, nil).permutation {break :ok})
       end
diff --git a/test/ruby/test_fiber.rb b/test/ruby/test_fiber.rb
index fed5d3d2c6..d1d15828fc 100644
--- a/test/ruby/test_fiber.rb
+++ b/test/ruby/test_fiber.rb
@@ -284,7 +284,7 @@ class TestFiber < Test::Unit::TestCase
     env['RUBY_FIBER_VM_STACK_SIZE'] = vm_stack_size.to_s if vm_stack_size
     env['RUBY_FIBER_MACHINE_STACK_SIZE'] = machine_stack_size.to_s if machine_stack_size
     out, _ = Dir.mktmpdir("test_fiber") {|tmpdir|
-      EnvUtil.invoke_ruby([env, '-e', script], '', true, true, chdir: tmpdir)
+      EnvUtil.invoke_ruby([env, '-e', script], '', true, true, chdir: tmpdir, timeout: 30)
     }
     use_length ? out.length : out
   end