diff --git a/ChangeLog b/ChangeLog
index 295f553f48..7af21fec75 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Sun Jan 25 00:42:24 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* ext/fiddle/win32/libffi.mk.tmpl: assemble without directory prefix.
+	  workaround of a bug of VC12 ml, by unak at [ruby-core:67792].
+	  [ruby-core:67789] [Bug #10780]
+
 Sat Jan 24 19:56:25 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* dln_find.c (dln_find_1): search regular files only.  based on
diff --git a/ext/fiddle/win32/libffi.mk.tmpl b/ext/fiddle/win32/libffi.mk.tmpl
index 412a75aec8..2a16e8efec 100755
--- a/ext/fiddle/win32/libffi.mk.tmpl
+++ b/ext/fiddle/win32/libffi.mk.tmpl
@@ -72,7 +72,7 @@ all: $(WORKDIR) $(STATICLIB)
 	$(CPP) $(CFLAGS) $(INCLUDES) $(<:\=/) >$(@:\=/)
 
 {$(BUILDDIR)/x86}.asm{$(BUILDDIR)/x86}.$(OBJEXT):
-	$(AS) -c $(ASFLAGS) -Fo $(@:\=/) $(<:\=/)
+	cd $(@D) && $(AS) -c $(ASFLAGS) -Fo $(@F) $(<F)
 
 $(BUILDDIR)/x86/$(OSSRC).asm: $(SRCDIR)/x86/$(OSSRC).S