1 files changed, 1 insertions, 2 deletions
diff --git a/ext/dl/extconf.rb b/ext/dl/extconf.rb
index 8bac1e83fb..abd8d8f781 100644
--- a/ext/dl/extconf.rb
+++ b/ext/dl/extconf.rb
@@ -25,8 +25,7 @@ else
   check = false
 end
 
-if( check )
-  have_func("rb_io_stdio_file", "ruby/ruby.h")
+if check
   $defs << %[-DRUBY_VERSION=\\"#{RUBY_VERSION}\\"]
   create_makefile("dl")
 end