$OpenBSD$

Index: lib/bgfx-cmake/bx/src/mutex.cpp
--- lib/bgfx-cmake/bx/src/mutex.cpp.orig
+++ lib/bgfx-cmake/bx/src/mutex.cpp
@@ -12,8 +12,10 @@
 	|| BX_PLATFORM_IOS     \
 	|| BX_PLATFORM_OSX     \
 	|| BX_PLATFORM_PS4     \
-	|| BX_PLATFORM_RPI
+	|| BX_PLATFORM_RPI	   \
+    || defined(__OpenBSD__)
 #	include <pthread.h>
+#   include <pthread_np.h>
 #elif  BX_PLATFORM_WINDOWS \
 	|| BX_PLATFORM_WINRT   \
 	|| BX_PLATFORM_XBOXONE
