diff --git a/dwm.c b/dwm.c
index cd11179..cac95ab 100644
--- a/dwm.c
+++ b/dwm.c
@@ -201,6 +201,7 @@ static void sendmon(Client *c, Monitor *m);
 static void setclientstate(Client *c, long state);
 static void setfocus(Client *c);
 static void setfullscreen(Client *c, int fullscreen);
+static void setgaps(const Arg *arg);
 static void setlayout(const Arg *arg);
 static void setmfact(const Arg *arg);
 static void setup(void);
@@ -1620,6 +1621,16 @@ setfullscreen(Client *c, int fullscreen)
 	}
 }
 
+void
+setgaps(const Arg *arg)
+{
+	if ((arg->i == 0) || (selmon->gappx + arg->i < 0))
+		selmon->gappx = 0;
+	else
+		selmon->gappx += arg->i;
+	arrange(selmon);
+}
+
 void
 setlayout(const Arg *arg)
 {