diff --git a/win32/Makefile.sub b/win32/Makefile.sub
index 76555f9193..3acdb1a2bd 100644
--- a/win32/Makefile.sub
+++ b/win32/Makefile.sub
@@ -1496,6 +1496,7 @@ rubyspec-capiext: $(RUBYSPEC_CAPIEXT_EXTS)
 	$(Q)$(LDSHARED_1)
 	$(Q)$(LDSHARED_2)
 !endif
+	$(Q)$(RM) $*.def $*.exp $*.lib $*.obj $*.pdb
 
 exts: rubyspec-capiext