diff --git a/ext/fiddle/fiddle.gemspec b/ext/fiddle/fiddle.gemspec
index 3a1072dd49..fc3cbfabc7 100644
--- a/ext/fiddle/fiddle.gemspec
+++ b/ext/fiddle/fiddle.gemspec
@@ -34,10 +34,6 @@ Gem::Specification.new do |spec|
     "ext/fiddle/memory_view.c",
     "ext/fiddle/pinned.c",
     "ext/fiddle/pointer.c",
-    "ext/fiddle/win32/fficonfig.h",
-    "ext/fiddle/win32/libffi-3.2.1-mswin.patch",
-    "ext/fiddle/win32/libffi-config.rb",
-    "ext/fiddle/win32/libffi.mk.tmpl",
     "fiddle.gemspec",
     "lib/fiddle.rb",
     "lib/fiddle/closure.rb",