diff --git a/configure.ac b/configure.ac
--- a/configure.ac
+++ b/configure.ac
@@ -678,6 +678,14 @@
  [ AC_MSG_RESULT(no)]
 )
 
+dnl Check for MSG_DONTWAIT
+AC_MSG_CHECKING(for MSG_DONTWAIT)
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <sys/socket.h>]],
+ [[ int f = MSG_DONTWAIT; ]])],
+ [ AC_MSG_RESULT(yes); AC_DEFINE(HAVE_MSG_DONTWAIT, 1,[Define this symbol if you have MSG_DONTWAIT]) ],
+ [ AC_MSG_RESULT(no)]
+)
+
 dnl Check for mallopt(M_ARENA_MAX) (to set glibc arenas)
 AC_MSG_CHECKING(for mallopt M_ARENA_MAX)
 AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <malloc.h>]],
diff --git a/src/compat.h b/src/compat.h
--- a/src/compat.h
+++ b/src/compat.h
@@ -47,10 +47,8 @@
 #include <unistd.h>
 #endif
 
-#ifdef WIN32
-#define MSG_DONTWAIT 0
-#else
-typedef u_int SOCKET;
+#ifndef WIN32
+typedef unsigned int SOCKET;
 #include "errno.h"
 #define WSAGetLastError() errno
 #define WSAEINVAL EINVAL
@@ -74,12 +72,6 @@
 #define MAX_PATH 1024
 #endif
 
-// As Solaris does not have the MSG_NOSIGNAL flag for send(2) syscall, it is
-// defined as 0
-#if !defined(HAVE_MSG_NOSIGNAL) && !defined(MSG_NOSIGNAL)
-#define MSG_NOSIGNAL 0
-#endif
-
 #if HAVE_DECL_STRNLEN == 0
 size_t strnlen(const char *start, size_t max_len);
 #endif // HAVE_DECL_STRNLEN
diff --git a/src/config/CMakeLists.txt b/src/config/CMakeLists.txt
--- a/src/config/CMakeLists.txt
+++ b/src/config/CMakeLists.txt
@@ -110,6 +110,10 @@
 check_symbol_exists(strnlen "string.h" HAVE_DECL_STRNLEN)
 check_symbol_exists(daemon "unistd.h" HAVE_DECL_DAEMON)
 
+# Check for socket.h support
+check_symbol_exists(MSG_NOSIGNAL "sys/socket.h" HAVE_MSG_NOSIGNAL)
+check_symbol_exists(MSG_DONTWAIT "sys/socket.h" HAVE_MSG_DONTWAIT)
+
 # OpenSSL functionality
 set(CMAKE_REQUIRED_INCLUDES ${OPENSSL_CRYPTO_INCLUDES})
 set(CMAKE_REQUIRED_LIBRARIES ${OPENSSL_CRYPTO_LIBRARY})
diff --git a/src/config/bitcoin-config.h.cmake.in b/src/config/bitcoin-config.h.cmake.in
--- a/src/config/bitcoin-config.h.cmake.in
+++ b/src/config/bitcoin-config.h.cmake.in
@@ -45,6 +45,9 @@
 #cmakedefine HAVE_DECL_STRNLEN 1
 #cmakedefine HAVE_DECL_DAEMON 1
 
+#cmakedefine HAVE_MSG_NOSIGNAL 1
+#cmakedefine HAVE_MSG_DONTWAIT 1
+
 #cmakedefine HAVE_DECL_EVP_MD_CTX_NEW 1
 
 #cmakedefine ENABLE_WALLET 1
diff --git a/src/net.cpp b/src/net.cpp
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -45,10 +45,16 @@
 // synchronization.
 #define FEELER_SLEEP_WINDOW 1
 
-#if !defined(HAVE_MSG_NOSIGNAL) && !defined(MSG_NOSIGNAL)
+#if !defined(HAVE_MSG_NOSIGNAL)
 #define MSG_NOSIGNAL 0
 #endif
 
+// MSG_DONTWAIT is not available on some platforms, if it doesn't exist define
+// it as 0
+#if !defined(HAVE_MSG_DONTWAIT)
+#define MSG_DONTWAIT 0
+#endif
+
 // Fix for ancient MinGW versions, that don't have defined these in ws2tcpip.h.
 // Todo: Can be removed when our pull-tester is upgraded to a modern MinGW
 // version.
diff --git a/src/netbase.cpp b/src/netbase.cpp
--- a/src/netbase.cpp
+++ b/src/netbase.cpp
@@ -25,7 +25,7 @@
 #include <boost/algorithm/string/case_conv.hpp> // for to_lower()
 #include <boost/algorithm/string/predicate.hpp> // for startswith() and endswith()
 
-#if !defined(HAVE_MSG_NOSIGNAL) && !defined(MSG_NOSIGNAL)
+#if !defined(HAVE_MSG_NOSIGNAL)
 #define MSG_NOSIGNAL 0
 #endif