diff --git a/ixwebsocket/IXNetSystem.h b/ixwebsocket/IXNetSystem.h
index b2220a95..21131b4e 100644
--- a/ixwebsocket/IXNetSystem.h
+++ b/ixwebsocket/IXNetSystem.h
@@ -12,8 +12,8 @@
 #define WIN32_LEAN_AND_MEAN
 #endif
 
-#include <WS2tcpip.h>
-#include <WinSock2.h>
+#include <ws2tcpip.h>
+#include <winsock2.h>
 #include <basetsd.h>
 #include <io.h>
 #include <ws2def.h>
diff --git a/ixwebsocket/IXSetThreadName.cpp b/ixwebsocket/IXSetThreadName.cpp
index 40faf9d9..b1e77379 100644
--- a/ixwebsocket/IXSetThreadName.cpp
+++ b/ixwebsocket/IXSetThreadName.cpp
@@ -17,7 +17,7 @@
 
 // Windows
 #ifdef _WIN32
-#include <Windows.h>
+#include <windows.h>
 #endif
 
 namespace ix
diff --git a/ixwebsocket/IXSocket.h b/ixwebsocket/IXSocket.h
index 5604c40d..393d5bc4 100644
--- a/ixwebsocket/IXSocket.h
+++ b/ixwebsocket/IXSocket.h
@@ -13,7 +13,7 @@
 #include <string>
 
 #ifdef _WIN32
-#include <BaseTsd.h>
+#include <basetsd.h>
 typedef SSIZE_T ssize_t;
 #endif
 
diff --git a/ixwebsocket/IXSocketOpenSSL.cpp b/ixwebsocket/IXSocketOpenSSL.cpp
index c92477a1..0028707e 100644
--- a/ixwebsocket/IXSocketOpenSSL.cpp
+++ b/ixwebsocket/IXSocketOpenSSL.cpp
@@ -15,7 +15,7 @@
 #include <errno.h>
 #include <vector>
 #ifdef _WIN32
-#include <Shlwapi.h>
+#include <shlwapi.h>
 #else
 #include <fnmatch.h>
 #endif
diff --git a/ixwebsocket/IXUdpSocket.h b/ixwebsocket/IXUdpSocket.h
index 048f9fc2..35f8fec4 100644
--- a/ixwebsocket/IXUdpSocket.h
+++ b/ixwebsocket/IXUdpSocket.h
@@ -11,7 +11,7 @@
 #include <string>
 
 #ifdef _WIN32
-#include <BaseTsd.h>
+#include <basetsd.h>
 typedef SSIZE_T ssize_t;
 #endif