diff --git a/mingw-w64-headers/include/afunix.h b/mingw-w64-headers/include/afunix.h
new file mode 100644
index 0000000..8a4f05f
--- /dev/null
+++ b/mingw-w64-headers/include/afunix.h
@@ -0,0 +1,19 @@
+/**
+ * This file has no copyright assigned and is placed in the Public Domain.
+ * This file is part of the mingw-w64 runtime package.
+ * No warranty is given; refer to the file DISCLAIMER.PD within this package.
+ */
+
+#ifndef _AFUNIX_
+#define _AFUNIX_
+
+#define UNIX_PATH_MAX 108
+
+typedef struct sockaddr_un {
+  ADDRESS_FAMILY sun_family;
+  char sun_path[UNIX_PATH_MAX];
+} SOCKADDR_UN, *PSOCKADDR_UN;
+
+#define SIO_AF_UNIX_GETPEERPID _WSAIOR(IOC_VENDOR, 256)
+
+#endif /* _AFUNIX_ */