Index: 3rdparty/pdfium/core/fxcrt/fx_system.h
--- 3rdparty/pdfium/core/fxcrt/fx_system.h.orig
+++ 3rdparty/pdfium/core/fxcrt/fx_system.h
@@ -43,6 +43,9 @@
 #elif defined(__linux__)
 #define _FX_OS_ _FX_LINUX_DESKTOP_
 #define _FXM_PLATFORM_ _FXM_PLATFORM_LINUX_
+#elif defined(__OpenBSD__)
+#define _FX_OS_ _FX_LINUX_DESKTOP_
+#define _FXM_PLATFORM_ _FXM_PLATFORM_LINUX_
 #elif defined(__APPLE__)
 #define _FX_OS_ _FX_MACOSX_
 #define _FXM_PLATFORM_ _FXM_PLATFORM_APPLE_
