diff --git a/ext/fiddle/depend b/ext/fiddle/depend
index 0513af4801..9146ef07a8 100644
--- a/ext/fiddle/depend
+++ b/ext/fiddle/depend
@@ -1,7 +1,6 @@
 PWD =
 
 CONFIGURE_LIBFFI = \
-	cd $(LIBFFI_DIR) && \
 	$(LIBFFI_CONFIGURE) --disable-shared \
 		--host=$(LIBFFI_ARCH) --enable-builddir=$(arch) \
 		CC="$(CC)" CFLAGS="$(LIBFFI_CFLAGS)" \
@@ -31,7 +30,7 @@ clean-libffi:
 distclean-libffi:
 	$(Q) $(SUBMAKE_LIBFFI) distclean
 	$(Q) $(RM) $(LIBFFI_DIR)/local.exp
-	$(Q) $(RUBY) -rfileutils -e 'FileUtils.rmdir(Dir.glob(ARGV[0]+"/**/"), :parents=>true)' $(LIBFFI_DIR)
+	$(Q) $(RUBY) -rfileutils -e "FileUtils.rmdir(Dir.glob(ARGV[0]+'/**/'), :parents=>true)" $(LIBFFI_DIR)
 
 realclean-libffi:
 	$(Q) $(RMALL) $(LIBFFI_DIR)
diff --git a/ext/fiddle/extconf.rb b/ext/fiddle/extconf.rb
index ca5fc35496..2bc5b8560d 100644
--- a/ext/fiddle/extconf.rb
+++ b/ext/fiddle/extconf.rb
@@ -47,25 +47,27 @@ begin
   libffi.arch = RbConfig::CONFIG['host']
   if $mswin
     $defs << "-DFFI_BUILDING"
-    libffi.opt = '-C'
-    cc = "#{libffi.srcdir}/msvcc.sh"
-    libffi.arch = libffi.arch.sub(/mswin\d+(_\d+)?\z/, 'mingw32')
-    cc << (libffi.arch.sub!(/^x64/, 'x86_64') ? " -m64" : " -m32")
-    libffi.ldflags = ''
-    cxx = cc
-    ld = "link"
-    cpp = "cl -nologo -EP"
+    libffi_config = "#{relative_from($srcdir, '..')}/win32/libffi-config.rb"
+    config = CONFIG.merge("top_srcdir" => $top_srcdir)
+    args = $ruby.gsub(/:\/=\\/, '')
+    args.gsub!(/\)\\/, ')/')
+    args = args.shellsplit
+    args.map! {|s| RbConfig.expand(s, config)}
+    args << '-C' << libffi.dir << libffi_config
+    opts = {}
   else
-    cc = RbConfig::CONFIG['CC']
-    ld = RbConfig::CONFIG['LD']
+    args = %W[sh #{libffi.srcdir}/configure ]
+    opts = {chdir: libffi.dir}
   end
-  args = %W[
-    sh #{libffi.srcdir}/configure
+  cc = RbConfig::CONFIG['CC']
+  cxx = RbConfig::CONFIG['CXX']
+  ld = RbConfig::CONFIG['LD']
+  args.concat %W[
+    --srcdir=#{libffi.srcdir}
     --disable-shared --host=#{libffi.arch}
     --enable-builddir=#{RUBY_PLATFORM}
   ]
   args << libffi.opt if libffi.opt
-  args << "CPP=#{cpp}" if cpp
   args.concat %W[
       CC=#{cc} CFLAGS=#{libffi.cflags}
       CXX=#{cxx} CXXFLAGS=#{RbConfig.expand("$(CXXFLAGS)", nowarn)}
@@ -74,8 +76,8 @@ begin
 
   FileUtils.rm_f("#{libffi.include}/ffitarget.h")
   Logging::open do
-    Logging.message("%p in %s\n", args, libffi.dir)
-    system(*args, chdir: libffi.dir) or
+    Logging.message("%p in %p\n", args, opts)
+    system(*args, **opts) or
       raise "failed to configure libffi. Please install libffi."
   end
   if $mswin && File.file?("#{libffi.include}/ffitarget.h")
@@ -131,18 +133,21 @@ end
 create_makefile 'fiddle' do |conf|
   if !libffi
     next conf << "LIBFFI_CLEAN = none\n"
-  elsif $mswin
-    submake = "make -C $(LIBFFI_DIR)\n"
-  elsif $gnumake
+  elsif $gnumake && !$nmake
     submake = "$(MAKE) -C $(LIBFFI_DIR)\n"
   else
     submake = "cd $(LIBFFI_DIR) && \\\n\t\t" << "#{config_string("exec")} $(MAKE)".strip
   end
+  if $nmake
+    cmd = "$(RUBY) -C $(LIBFFI_DIR) #{libffi_config} --srcdir=$(LIBFFI_SRCDIR)"
+  else
+    cmd = "cd $(LIBFFI_DIR) && #$exec $(LIBFFI_SRCDIR)/configure #{libffi.opt}"
+  end
   sep = "/"
   seprpl = config_string('BUILD_FILE_SEPARATOR') {|s| sep = s; ":/=#{s}" if s != "/"} || ""
   conf << <<-MK.gsub(/^ +| +$/, '')
    PWD =
-   LIBFFI_CONFIGURE = $(LIBFFI_SRCDIR#{seprpl})#{sep}configure #{libffi.opt}
+   LIBFFI_CONFIGURE = #{cmd}
    LIBFFI_ARCH = #{libffi.arch}
    LIBFFI_SRCDIR = #{libffi.srcdir}
    LIBFFI_DIR = #{libffi.dir}
diff --git a/ext/fiddle/win32/fficonfig.h b/ext/fiddle/win32/fficonfig.h
new file mode 100755
index 0000000000..776808159c
--- /dev/null
+++ b/ext/fiddle/win32/fficonfig.h
@@ -0,0 +1,29 @@
+#define HAVE_ALLOCA 1
+#define HAVE_MEMCPY 1
+#define HAVE_MEMORY_H 1
+#define HAVE_STDLIB_H 1
+#define HAVE_STRING_H 1
+#define HAVE_SYS_STAT_H 1
+#define HAVE_SYS_TYPES_H 1
+#if _MSC_VER >= 1600
+#define HAVE_INTTYPES_H 1
+#define HAVE_STDINT_H 1
+#endif
+
+#define SIZEOF_DOUBLE 8
+#if defined(X86_WIN64)
+#define SIZEOF_SIZE_T 8
+#else
+#define SIZEOF_SIZE_T 4
+#endif
+
+#define STACK_DIRECTION -1
+
+#define STDC_HEADERS 1
+
+#ifdef LIBFFI_ASM
+#define FFI_HIDDEN(name)
+#else
+#define FFI_HIDDEN
+#endif
+
diff --git a/ext/fiddle/win32/libffi-config.rb b/ext/fiddle/win32/libffi-config.rb
new file mode 100755
index 0000000000..ecd3b086c0
--- /dev/null
+++ b/ext/fiddle/win32/libffi-config.rb
@@ -0,0 +1,47 @@
+#!/usr/bin/ruby
+require 'fileutils'
+
+basedir = File.dirname(__FILE__)
+conf = {}
+enable = {}
+until ARGV.empty?
+  arg = ARGV.shift
+  case arg
+  when '-C'
+    # ignore
+  when /\A--srcdir=(.*)/
+    conf['SRCDIR'] = srcdir = $1
+  when /\A(CC|CFLAGS|CXX|CXXFLAGS|LD|LDFLAGS)=(.*)/
+    conf[$1] = $2
+  when /\A--host=(.*)/
+    host = $1
+  when /\A--enable-([^=]+)(?:=(.*))?/
+    enable[$1] = $2 || true
+  when /\A--disable-([^=]+)/
+    enable[$1] = false
+  end
+end
+
+IO.foreach("#{srcdir}/configure.ac") do |line|
+  if /^AC_INIT\((.*)\)/ =~ line
+    version = $1.split(/,\s*/)[1]
+    version.gsub!(/\A\[|\]\z/, '')
+    conf['VERSION'] = version
+    break
+  end
+end
+
+builddir = srcdir == "." ? enable['builddir'] : "."
+conf['TARGET'] = /^x64/ =~ host ? "X86_WIN64" : "X86_WIN32"
+
+FileUtils.mkdir_p([builddir, "#{builddir}/include", "#{builddir}/src/x86"])
+FileUtils.cp("#{basedir}/fficonfig.h", ".", preserve: true)
+
+hdr = IO.binread("#{srcdir}/include/ffi.h.in")
+hdr.gsub!(/@(\w+)@/) {conf[$1] || $&}
+hdr.gsub!(/^(#if\s+)@\w+@/, '\10')
+IO.binwrite("#{builddir}/include/ffi.h", hdr)
+
+mk = IO.binread("#{basedir}/libffi.mk.tmpl")
+mk.gsub!(/@(\w+)@/) {conf[$1] || $&}
+IO.binwrite("Makefile", mk)
diff --git a/ext/fiddle/win32/libffi.mk.tmpl b/ext/fiddle/win32/libffi.mk.tmpl
new file mode 100755
index 0000000000..621451e7a2
--- /dev/null
+++ b/ext/fiddle/win32/libffi.mk.tmpl
@@ -0,0 +1,96 @@
+# -*- makefile -*-
+# ====================================================================
+#
+# libffi Windows Makefile
+#
+#
+# ====================================================================
+#
+NAME	= ffi
+TARGET	= @TARGET@
+CC	= cl
+!if "$(TARGET)" == "X86_WIN64"
+AS	= ml64
+!else
+AS	= ml
+!endif
+AR	= link
+DLEXT	= dll
+OBJEXT	= obj
+LIBEXT	= lib
+TOPDIR	= @SRCDIR@
+CPP	= $(CC) -EP
+CFLAGS	= @CFLAGS@
+ARFLAGS	= -lib
+ASFLAGS	= -coff -W3 -Cx
+INCLUDES= -I. -I./include -I./src/x86 \
+	  -I$(TOPDIR)/include -I$(TOPDIR)/include/src/x86
+
+SRCDIR	= $(TOPDIR)/src
+WORKDIR	= ./.libs
+BUILDDIR= ./src
+LIBNAME	= lib$(NAME)
+STATICLIB= $(WORKDIR)/$(LIBNAME).$(LIBEXT)
+
+HEADERS = \
+	./fficonfig.h
+FFI_HEADERS = \
+	./include/ffi.h \
+	./include/ffitarget.h
+
+!if "$(TARGET)" == "X86_WIN32"
+OSSRC	= win32
+!else if "$(TARGET)" == "X86_WIN64"
+OSSRC	= win64
+!else
+! error unknown target: $(TARGET)
+!endif
+
+OBJECTS = \
+	$(BUILDDIR)/closures.$(OBJEXT) \
+	$(BUILDDIR)/debug.$(OBJEXT) \
+	$(BUILDDIR)/java_raw_api.$(OBJEXT) \
+	$(BUILDDIR)/prep_cif.$(OBJEXT) \
+	$(BUILDDIR)/raw_api.$(OBJEXT) \
+	$(BUILDDIR)/types.$(OBJEXT) \
+	$(BUILDDIR)/x86/ffi.$(OBJEXT) \
+	$(BUILDDIR)/x86/$(OSSRC).$(OBJEXT)
+ASMSRCS = \
+	$(BUILDDIR)/x86/$(OSSRC).asm
+
+.SUFFIXES : .S .asm
+
+all: $(WORKDIR) $(STATICLIB)
+
+{$(SRCDIR)}.c{$(BUILDDIR)}.$(OBJEXT):
+	$(CC) -c $(CFLAGS) $(INCLUDES) -Fo$(@:\=/) -Fd$(WORKDIR)/$(NAME)-src $(<:\=/)
+
+{$(SRCDIR)/x86}.c{$(BUILDDIR)/x86}.$(OBJEXT):
+	$(CC) -c $(CFLAGS) $(INCLUDES) -Fo$(@:\=/) -Fd$(WORKDIR)/$(NAME)-src $(<:\=/)
+
+{$(SRCDIR)/x86}.S{$(BUILDDIR)/x86}.asm:
+	$(CPP) $(CFLAGS) $(INCLUDES) $(<:\=/) >$(@:\=/)
+
+{$(BUILDDIR)/x86}.asm{$(BUILDDIR)/x86}.$(OBJEXT):
+	$(AS) -c $(ASFLAGS) -Fo $(@:\=/) $(<:\=/)
+
+$(BUILDDIR)/x86/$(OSSRC).asm: $(SRCDIR)/x86/$(OSSRC).S
+
+$(OBJECTS): $(FFI_HEADERS) $(HEADERS)
+
+$(WORKDIR):
+	-@if not exist "$(WORKDIR:/=\)\$(NULL)" mkdir $(WORKDIR:/=\)
+
+$(STATICLIB): $(WORKDIR) $(OBJECTS)
+	$(AR) $(ARFLAGS) -out:$(STATICLIB) @<<
+	$(OBJECTS)
+<<
+
+clean:
+	-@del /Q $(OBJECTS:/=\) 2>NUL
+	-@del /Q $(ASMSRCS:/=\) 2>NUL
+	-@del /Q /S $(WORKDIR:/=\) 2>NUL
+
+distclean: clean
+	-@del /Q $(HEADERS:/=\) $(FFI_HEADERS:/=\) 2>NUL
+	-@del /Q Makefile 2>NUL