--- a/config.mk
+++ b/config.mk
@@ -4,18 +4,18 @@ VERSION = 2.1
 # Customize below to fit your system
 
 # paths
-PREFIX = /usr/local
+PREFIX = /usr
 MANPREFIX = $(PREFIX)/share/man
 LIBPREFIX = $(PREFIX)/lib
 LIBDIR = $(LIBPREFIX)/surf
 
-X11INC = `pkg-config --cflags x11`
-X11LIB = `pkg-config --libs x11`
+X11INC = $(shell $(PKG_CONFIG) --cflags x11)
+X11LIB = $(shell $(PKG_CONFIG) --libs x11)
 
-GTKINC = `pkg-config --cflags gtk+-3.0 gcr-3 webkit2gtk-4.0`
-GTKLIB = `pkg-config --libs gtk+-3.0 gcr-3 webkit2gtk-4.0`
-WEBEXTINC = `pkg-config --cflags webkit2gtk-4.0 webkit2gtk-web-extension-4.0 gio-2.0`
-WEBEXTLIBS = `pkg-config --libs webkit2gtk-4.0 webkit2gtk-web-extension-4.0 gio-2.0`
+GTKINC = $(shell $(PKG_CONFIG) --cflags gtk+-3.0 gcr-3 webkit2gtk-4.1)
+GTKLIB = $(shell $(PKG_CONFIG) --libs gtk+-3.0 gcr-3 webkit2gtk-4.1)
+WEBEXTINC = $(shell $(PKG_CONFIG) --cflags webkit2gtk-4.1 webkit2gtk-web-extension-4.1 gio-2.0)
+WEBEXTLIBS = $(shell $(PKG_CONFIG) --libs webkit2gtk-4.1 webkit2gtk-web-extension-4.1 gio-2.0)
 
 # includes and libs
 INCS = $(X11INC) $(GTKINC)