diff --git a/windows/utf16.cpp b/windows/utf16.cpp
index 131759e9..143bad24 100644
--- a/windows/utf16.cpp
+++ b/windows/utf16.cpp
@@ -1,6 +1,13 @@
 // 21 april 2016
 #include "uipriv_windows.hpp"
 
+// sanity check - make sure wchar_t is 16 bits (the assumption on windows)
+// (MinGW-w64 gcc does seem to define a 16bit wchar_t, but you never know. Other windows gcc ports might not)
+#if WCHAR_MAX > 0xFFFF
+  #error wchar_t larger than 16bit
+#endif
+
+
 // see http://stackoverflow.com/a/29556509/3408572
 
 WCHAR *toUTF16(const char *str)
diff --git a/windows/winapi.hpp b/windows/winapi.hpp
index 1b2ab000..909aa56b 100644
--- a/windows/winapi.hpp
+++ b/windows/winapi.hpp
@@ -23,6 +23,13 @@
 #define _WIN32_IE			0x0700
 #define NTDDI_VERSION		0x06000000
 
+// the msys2 header has an unverified IDWriteTypography definition.
+// Would be good to get it verified and fixed in msys2, but in the meantime,
+// this define lets us compile....
+#if !defined(_MSC_VER)
+#define __MINGW_USE_BROKEN_INTERFACE
+#endif
+
 #include <windows.h>
 
 // Microsoft's resource compiler will segfault if we feed it headers it was not designed to handle