Index: src/slic3r/Utils/Process.cpp
--- src/slic3r/Utils/Process.cpp.orig
+++ src/slic3r/Utils/Process.cpp
@@ -86,7 +86,7 @@ static void start_new_slicer_or_gcodeviewer(const NewS
 	{
 		std::vector<const char*> args;
 		args.reserve(3);
-#ifdef __linux__
+#if defined(__linux__) || defined(__OpenBSD__)
 		static const char* gcodeviewer_param = "--gcodeviewer";
 		{
 			// If executed by an AppImage, start the AppImage, not the main process.
