error make surf2

hi,
i cant compile surf2 from suckless.org, a great simple browser
surf1 is in repository but it is old and useless
in other distributions compile works. is something missing?
pls help.

surf.c: In function ‘setup’:
surf.c:344:10: warning: implicit declaration of function ‘gdk_seat_get_keyboard’ [-Wimplicit-function-declaration]
gdkkb = gdk_seat_get_keyboard(gdk_display_get_default_seat(gdpy));
^
surf.c:344:32: warning: implicit declaration of function ‘gdk_display_get_default_seat’ [-Wimplicit-function-declaration]
gdkkb = gdk_seat_get_keyboard(gdk_display_get_default_seat(gdpy));
^
surf.c:344:8: warning: assignment makes pointer from integer without a cast [-Wint-conversion]
gdkkb = gdk_seat_get_keyboard(gdk_display_get_default_seat(gdpy));
^
surf.c: In function ‘msgext’:
surf.c:1851:40: warning: format ‘%c’ expects argument of type ‘int’, but argument 5 has type ‘long unsigned int’ [-Wformat=]
if ((ret = snprintf(msg, sizeof(msg), "%c%c%c%c",
^
surf.c:1851:40: warning: format ‘%c’ expects argument of type ‘int’, but argument 5 has type ‘long unsigned int’ [-Wformat=]
c99 -o surf surf.o common.o `pkg-config --libs x11` `pkg-config --libs gtk+-3.0 gcr-3 webkit2gtk-4.0` -lgthread-2.0
surf.o: In function `main':
surf.c:(.text+0x35df): undefined reference to `gdk_display_get_default_seat'
surf.c:(.text+0x35eb): undefined reference to `gdk_seat_get_keyboard'
collect2: error: ld returned 1 exit status
Makefile:41: recipe for target 'surf' failed
make: *** [surf] Error 1