diff --git a/test/stringio/test_stringio.rb b/test/stringio/test_stringio.rb
index a2778907c8..c83e8c9ec4 100644
--- a/test/stringio/test_stringio.rb
+++ b/test/stringio/test_stringio.rb
@@ -692,7 +692,7 @@ class TestStringIO < Test::Unit::TestCase
         x = "a"*0x100000
         break if [x].pack("p").unpack("i!")[0] < 0
         ary << x
-        skip if ary.size > 1000
+        skip if ary.size > 100
       end
       s = StringIO.new(x)
       s.gets("xxx", limit)