diff --git a/CMakeLists.txt b/CMakeLists.txt
index bd3b506..560ffb2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -546,6 +546,12 @@ IF(ENABLE_HARU AND HARU_FOUND)
   SET(WT_HAS_WPDFIMAGE true)
 ENDIF(ENABLE_HARU AND HARU_FOUND)
 
+if (WIN32)
+    add_definitions(-DWT_WIN32)
+endif()
+find_package(OpenSSL REQUIRED)
+set(OPENSSL_FOUND OpenSSL_FOUND)
+set(OPENSSL_LIBRARIES OpenSSL::SSL OpenSSL::Crypto)
 IF(ENABLE_SSL AND OPENSSL_FOUND)
   SET(HAVE_SSL ON)
   SET(WT_WITH_SSL true)
diff --git a/src/isapi/IsapiRequest.h b/src/isapi/IsapiRequest.h
index 6c788e2..3f8d213 100644
--- a/src/isapi/IsapiRequest.h
+++ b/src/isapi/IsapiRequest.h
@@ -1,5 +1,8 @@
 #include "WebRequest.h"
 #include <sstream>
+#ifdef _WIN32
+#include <winsock2.h>
+#endif
 #include <httpext.h>
 
 namespace Wt {
