diff --git a/include/stdio.h b/include/stdio.h
index 989b7fc..ab17883 100644
--- a/include/stdio.h
+++ b/include/stdio.h
@@ -14,4 +14,17 @@ int vasprintf(char **str, const char *fmt, va_list ap);
 int asprintf(char **str, const char *fmt, ...);
 #endif
 
+#ifdef _WIN32
+#include <errno.h>
+#include <string.h>
+
+static inline void
+posix_perror(const char *s)
+{
+	fprintf(stderr, "%s: %s\n", s, strerror(errno));
+}
+
+#define perror(errnum) posix_perror(errnum)
+#endif
+
 #endif
diff --git a/include/string.h b/include/string.h
index a3263e7..c558a90 100644
--- a/include/string.h
+++ b/include/string.h
@@ -50,4 +50,20 @@ void * memmem(const void *big, size_t big_len, const void *little,
 	size_t little_len);
 #endif
 
+#ifdef _WIN32
+#include <errno.h>
+
+static inline char  *
+posix_strerror(int errnum)
+{
+	if (errnum == ECONNREFUSED) {
+		return "Connection refused";
+	}
+	return strerror(errnum);
+}
+
+#define strerror(errnum) posix_strerror(errnum)
+
+#endif
+
 #endif
diff --git a/include/win32netcompat.h b/include/win32netcompat.h
index 3c716b0..51384d0 100644
--- a/include/win32netcompat.h
+++ b/include/win32netcompat.h
@@ -1,3 +1,10 @@
+/*
+ * Public domain
+ *
+ * BSD socket emulation code for Winsock2
+ * Brent Cook <bcook@openbsd.org>
+ */
+
 #ifndef LIBCRYPTOCOMPAT_WIN32NETCOMPAT_H
 #define LIBCRYPTOCOMPAT_WIN32NETCOMPAT_H
 
@@ -5,17 +12,149 @@
 
 #include <ws2tcpip.h>
 
-#ifndef SHUT_RDWR
 #define SHUT_RDWR SD_BOTH
-#endif
+#define SHUT_RD   SD_RECEIVE
+#define SHUT_WR   SD_SEND
 
-#ifndef SHUT_RD
-#define SHUT_RD SD_RECEIVE
-#endif
+#include <errno.h>
+#include <unistd.h>
 
-#ifndef SHUT_WR
-#define SHUT_WR SD_SEND
-#endif
+static int
+wsa_errno(int err)
+{
+	switch (err) {
+	case WSAENOBUFS:
+		errno = ENOMEM;
+		break;
+	case WSAEACCES:
+		errno = EACCES;
+		break;
+	case WSANOTINITIALISED:
+		errno = EPERM;
+		break;
+	case WSAEHOSTUNREACH:
+	case WSAENETDOWN:
+		errno = EIO;
+		break;
+	case WSAEFAULT:
+		errno = EFAULT;
+		break;
+	case WSAEINTR:
+		errno = EINTR;
+		break;
+	case WSAEINVAL:
+		errno = EINVAL;
+		break;
+	case WSAEINPROGRESS:
+		errno = EINPROGRESS;
+		break;
+	case WSAEWOULDBLOCK:
+		errno = EAGAIN;
+		break;
+	case WSAEOPNOTSUPP:
+		errno = ENOTSUP;
+		break;
+	case WSAEMSGSIZE:
+		errno = EFBIG;
+		break;
+	case WSAENOTSOCK:
+		errno = ENOTSOCK;
+		break;
+	case WSAENOPROTOOPT:
+		errno = ENOPROTOOPT;
+		break;
+	case WSAECONNREFUSED:
+		errno = ECONNREFUSED;
+		break;
+	case WSAEAFNOSUPPORT:
+		errno = EAFNOSUPPORT;
+		break;
+	case WSAENETRESET:
+	case WSAENOTCONN:
+	case WSAECONNABORTED:
+	case WSAECONNRESET:
+	case WSAESHUTDOWN:
+	case WSAETIMEDOUT:
+		errno = EPIPE;
+		break;
+	}
+	return -1;
+}
+
+static inline int
+posix_connect(int sockfd, const struct sockaddr *addr, socklen_t addrlen)
+{
+	int rc = connect(sockfd, addr, addrlen);
+	if (rc == SOCKET_ERROR)
+		return wsa_errno(WSAGetLastError());
+	return rc;
+}
+
+#define connect(sockfd, addr, addrlen) posix_connect(sockfd, addr, addrlen)
+
+static inline int
+posix_close(int fd)
+{
+	if (closesocket(fd) == SOCKET_ERROR) {
+		int err = WSAGetLastError();
+		return err == WSAENOTSOCK ?
+			close(fd) : wsa_errno(err);
+	}
+	return 0;
+}
+
+#define close(fd) posix_close(fd)
+
+static inline ssize_t
+posix_read(int fd, void *buf, size_t count)
+{
+	ssize_t rc = recv(fd, buf, count, 0);
+	if (rc == SOCKET_ERROR) {
+		int err = WSAGetLastError();
+		return err == WSAENOTSOCK ?
+			read(fd, buf, count) : wsa_errno(err);
+	}
+	return rc;
+}
+
+#define read(fd, buf, count) posix_read(fd, buf, count)
+
+static inline ssize_t
+posix_write(int fd, const void *buf, size_t count)
+{
+	ssize_t rc = send(fd, buf, count, 0);
+	if (rc == SOCKET_ERROR) {
+		int err = WSAGetLastError();
+		return err == WSAENOTSOCK ?
+			write(fd, buf, count) : wsa_errno(err);
+	}
+	return rc;
+}
+
+#define write(fd, buf, count) posix_write(fd, buf, count)
+
+static inline int
+posix_getsockopt(int sockfd, int level, int optname,
+	void *optval, socklen_t *optlen)
+{
+	int rc = getsockopt(sockfd, level, optname, (char *)optval, optlen);
+	return rc == 0 ? 0 : wsa_errno(WSAGetLastError());
+
+}
+
+#define getsockopt(sockfd, level, optname, optval, optlen) \
+	posix_getsockopt(sockfd, level, optname, optval, optlen)
+
+static inline int
+posix_setsockopt(int sockfd, int level, int optname,
+	const void *optval, socklen_t optlen)
+{
+	int rc = setsockopt(sockfd, level, optname, (char *)optval, optlen);
+	return rc == 0 ? 0 : wsa_errno(WSAGetLastError());
+}
+
+#define setsockopt(sockfd, level, optname, optval, optlen) \
+	posix_setsockopt(sockfd, level, optname, optval, optlen)
 
 #endif