Copy configuration below to ~/Library/LaunchAgents/com.local.KeyRemapping.plist <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"> <plist version="1.0"> <dict> <key>Label</key> <string>com.local.KeyRemapping</string> <key>ProgramArguments</key> <array> <string>/usr/bin/hidutil</string> <string>property</string> <string>--set</string> <string>{"UserKeyMapping":[ { "HIDKeyboardModifierMappingSrc": 0xFF00000003, "HIDKeyboardModifierMappingDst": 0x700000055 } ]}</string> </array> <key>RunAtLoad</key> <true/> </dict> </plist> Reboot Go to System Settings -> Keyboard -> Keyboard Shorcuts -> Input Sources -> Select Next Source -> Click Fn If you use keyboard with a numpad you would better change 0x700000055 to something else. Google hdutil.