diff -rupN Python-2.7.14/Lib/distutils/cygwinccompiler.py Python-2.7.14-new/Lib/distutils/cygwinccompiler.py
--- Python-2.7.14/Lib/distutils/cygwinccompiler.py	2017-10-31 18:36:35.489182303 +0100
+++ Python-2.7.14-new/Lib/distutils/cygwinccompiler.py	2017-10-31 18:36:35.491182302 +0100
@@ -85,6 +85,7 @@ class CygwinCCompiler (UnixCCompiler):
     obj_extension = ".o"
     static_lib_extension = ".a"
     shared_lib_extension = ".dll"
+    dylib_lib_extension = ".dll.a"
     static_lib_format = "lib%s%s"
     shared_lib_format = "%s%s"
     exe_extension = ".exe"