diff --git a/Misc/NEWS.d/next/Library/2020-07-27-19-21-05.bpo-41374.cd-kFL.rst b/Misc/NEWS.d/next/Library/2020-07-27-19-21-05.bpo-41374.cd-kFL.rst
new file mode 100644
index 00000000000000..a5b2e042a3faec
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2020-07-27-19-21-05.bpo-41374.cd-kFL.rst
@@ -0,0 +1,2 @@
+Ensure that ``socket.TCP_*`` constants are exposed on Cygwin 3.1.6 and
+greater.
diff --git a/Modules/socketmodule.h b/Modules/socketmodule.h
index ba2c9f5c31c3b1..f565b8e1396ff8 100644
--- a/Modules/socketmodule.h
+++ b/Modules/socketmodule.h
@@ -8,9 +8,7 @@
 #   include <sys/socket.h>
 # endif
 # include <netinet/in.h>
-# if !defined(__CYGWIN__)
-#  include <netinet/tcp.h>
-# endif
+# include <netinet/tcp.h>
 
 #else /* MS_WINDOWS */
 # include <winsock2.h>