diff --git a/ext/fiddle/extlibs b/ext/fiddle/extlibs
index 7d5fda5247..92025952da 100644
--- a/ext/fiddle/extlibs
+++ b/ext/fiddle/extlibs
@@ -1,2 +1,5 @@
-ftp://sourceware.org/pub/libffi/libffi-3.2.1.tar.gz md5:83b89587607e3eb65c70d361f13bab43
+ftp://sourceware.org/pub/libffi/libffi-3.2.1.tar.gz \
+  md5:83b89587607e3eb65c70d361f13bab43 \
+  sha512:980ca30a8d76f963fca722432b1fe5af77d7a4e4d2eac5144fbc5374d4c596609a293440573f4294207e1bdd9fda80ad1e1cafb2ffb543df5a275bc3bd546483 \
+  #
 	win32/libffi-3.2.1-mswin.patch -p0
diff --git a/tool/extlibs.rb b/tool/extlibs.rb
index d59a139b0f..10609ebb16 100755
--- a/tool/extlibs.rb
+++ b/tool/extlibs.rb
@@ -142,16 +142,24 @@ class ExtLibs
         end
         extracted = false
         dest = File.dirname(list)
+        url = chksums = nil
         IO.foreach(list) do |line|
           line.sub!(/\s*#.*/, '')
-          if /^\t/ =~ line
+          if chksums
+            chksums.concat(line.split)
+          elsif /^\t/ =~ line
             if extracted and (mode == :all or mode == :patch)
               patch, *args = line.split
               do_patch(dest, patch, args)
             end
             next
+          else
+            url, *chksums = line.split(' ')
+          end
+          if chksums.last == '\\'
+            chksums.pop
+            next
           end
-          url, *chksums = line.split(' ')
           next unless url
           begin
             extracted = do_command(mode, dest, url, cache_dir, chksums)
@@ -159,6 +167,7 @@ class ExtLibs
             warn e.inspect
             success = false
           end
+          url = chksums = nil
         end
       end
     end