diff --git a/test/ruby/test_array.rb b/test/ruby/test_array.rb
index eacc0b0..2c00d00 100644
--- a/test/ruby/test_array.rb
+++ b/test/ruby/test_array.rb
@@ -1823,7 +1823,8 @@ def test_permutation
 
   def test_permutation_stack_error
     bug9932 = '[ruby-core:63103] [Bug #9932]'
-    assert_separately([], <<-"end;") #    do
+    # On some platforms (armel, mips), permutation is very expensive/slow.
+    assert_separately([], <<-"end;", timeout: 60) #    do
       assert_nothing_raised(SystemStackError, "#{bug9932}") do
         assert_equal(:ok, Array.new(100_000, nil).permutation {break :ok})
       end