diff --git a/OSlibs/win/mingw.h b/OSlibs/win/mingw.h
index ff80c1b3f..a28dbbe25 100755
--- a/OSlibs/win/mingw.h
+++ b/OSlibs/win/mingw.h
@@ -5,7 +5,11 @@
 #include <io.h>
 
 #define _USE_W32_SOCKETS 1
+
+#ifdef MM_WIN_BUILD
 #include <winsock2.h>
+#endif
+
 #include <windows.h>
 #define PTW32_STATIC_LIB
 #include "pthread.h"
diff --git a/crypto777/CMakeLists.txt b/crypto777/CMakeLists.txt
index ac2316e04..979f301c8 100644
--- a/crypto777/CMakeLists.txt
+++ b/crypto777/CMakeLists.txt
@@ -7,5 +7,6 @@ if(WIN32)
 add_definitions(-DNATIVE_WINDOWS)
 add_definitions(-DIGUANA_LOG2PACKETSIZE=20)
 add_definitions(-DIGUANA_MAXPACKETSIZE=1572864)
+add_definitions(-DMM_WIN_BUILD)
 include_directories("${CMAKE_SOURCE_DIR}/includes")
 endif()
diff --git a/iguana/exchanges/CMakeLists.txt b/iguana/exchanges/CMakeLists.txt
index 89516c4fd..72cc2ac4c 100644
--- a/iguana/exchanges/CMakeLists.txt
+++ b/iguana/exchanges/CMakeLists.txt
@@ -24,6 +24,7 @@ add_definitions(-DNATIVE_WINDOWS)
 add_definitions(-DIGUANA_LOG2PACKETSIZE=20)
 add_definitions(-DIGUANA_MAXPACKETSIZE=1572864)
 add_definitions(-D_CRT_SECURE_NO_WARNINGS)
+add_definitions(-DMM_WIN_BUILD)
 include_directories("${CMAKE_SOURCE_DIR}/includes")
 endif()
 target_link_libraries(marketmaker-testnet ${MM_LIBS} etomiclib-testnet)