--- a/xpcom/reflect/xptcall/md/unix/moz.build
+++ b/xpcom/reflect/xptcall/md/unix/moz.build
@@ -19,17 +19,17 @@ if CONFIG['OS_ARCH'] == 'Darwin':
 
 if CONFIG['OS_ARCH'] == 'GNU':
     if CONFIG['CPU_ARCH'] == 'x86':
         SOURCES += [
             'xptcinvoke_gcc_x86_unix.cpp',
             'xptcstubs_gcc_x86_unix.cpp'
         ]
 
-if CONFIG['OS_ARCH'] in ('Linux', 'FreeBSD', 'NetBSD', 'OpenBSD') or \
+if CONFIG['OS_ARCH'] in ('Linux', 'Bitrig', 'DragonFly', 'FreeBSD', 'NetBSD', 'OpenBSD') or \
    CONFIG['OS_ARCH'].startswith('GNU_'):
     if CONFIG['OS_TEST'] == 'x86_64':
         SOURCES += [
             'xptcinvoke_x86_64_unix.cpp',
             'xptcstubs_x86_64_linux.cpp',
         ]
     elif '86' in CONFIG['OS_TEST']:
         SOURCES += [
@@ -97,17 +97,17 @@ if CONFIG['CPU_ARCH'] == 'arm' or CONFIG
         ]
         CXXFLAGS += ['-O2']
     elif CONFIG['OS_ARCH'] == 'NetBSD':
         SOURCES += [
             'xptcinvoke_arm_netbsd.cpp',
             'xptcstubs_arm_netbsd.cpp',
         ]
 
-if CONFIG['CPU_ARCH'] == 'arm' and CONFIG['OS_ARCH'] == 'OpenBSD':
+if CONFIG['CPU_ARCH'] == 'arm' and CONFIG['OS_ARCH'] in ('Bitrig', 'OpenBSD'):
     SOURCES += [
         'xptcinvoke_arm_openbsd.cpp',
         'xptcstubs_arm_openbsd.cpp',
     ]
 
 if CONFIG['OS_ARCH'] == 'HP-UX':
     if CONFIG['CC'] != 'gcc':
         if CONFIG['OS_TEST'] == 'ia64':