1 files changed, 8 insertions, 0 deletions
diff --git a/ext/curses/extconf.rb b/ext/curses/extconf.rb
index 3e53ef65f7..a95b49ffea 100644
--- a/ext/curses/extconf.rb
+++ b/ext/curses/extconf.rb
@@ -129,5 +129,13 @@ if header_library
     warn "unexpeted value for --with-curses-version: #{with_curses_version}"
   end
 
+  for type in ["long", "int"]
+    if try_static_assert("sizeof(chtype) == sizeof(unsigned #{type})",
+                         %w[stdio.h stdlib.h]+curses)
+      $defs << "-DCHTYPE_IS_U#{type.upcase}"
+      break
+    end
+  end
+
   create_makefile("curses")
 end