diff --git a/include/bx/os.h b/include/bx/os.h
index 7baad6f..874f02c 100644
--- a/include/bx/os.h
+++ b/include/bx/os.h
@@ -11,6 +11,7 @@
 
 #if BX_PLATFORM_WINDOWS || BX_PLATFORM_WINRT
 #	include <windows.h>
+#	include <psapi.h>
 #elif  BX_PLATFORM_ANDROID \
 	|| BX_PLATFORM_EMSCRIPTEN \
 	|| BX_PLATFORM_FREEBSD \