diff --git a/distutils/unixccompiler.py b/distutils/unixccompiler.py
index df622cd4..7e68596b 100644
--- a/distutils/unixccompiler.py
+++ b/distutils/unixccompiler.py
@@ -144,6 +144,9 @@ class UnixCCompiler(CCompiler):
     xcode_stub_lib_format = dylib_lib_format
     if sys.platform == "cygwin":
         exe_extension = ".exe"
+        shared_lib_extension = ".dll.a"
+        dylib_lib_extension = ".dll"
+        dylib_lib_format = "cyg%s%s"
 
     def preprocess(
         self,