diff --git a/config.def.h b/config.def.h
index 230e701..45a78c8 100644
--- a/config.def.h
+++ b/config.def.h
@@ -26,7 +26,7 @@ static Rule rules[] = {
 };
 
 /* layout(s) */
-static int mwp          = 55;   /* master area width percentage [5..95] */
+static int mwp          = 55;   /* master area width percentage [5..100] */
 static int mn           = 1;    /* number of clients in master area */
 static Bool resizehints = True; /* False means respect size hints in tiled resizals */
 
diff --git a/dwm.c b/dwm.c
index ad1886d..3f34965 100644
--- a/dwm.c
+++ b/dwm.c
@@ -191,7 +191,7 @@ static void togglebar(const Arg *arg);
 static void togglefloating(const Arg *arg);
 static void toggletag(const Arg *arg);
 static void toggleview(const Arg *arg);
-static void tweak(int *var, const int *val, int min, int max);
+static void tweak(int *ip, int i, int min, int max);
 static void tweakmwp(const Arg *arg);
 static void tweakmn(const Arg *arg);
 static void unmanage(Client *c);
@@ -1481,24 +1481,29 @@ toggleview(const Arg *arg) {
 }
 
 void
-tweak(int *var, const int *val, int min, int max) {
-	int i;
-
-	i = val[1] + (val[0] == Abs ? 0 : *var);
-	if(!lt[sellt]->arrange || i < min || i > max)
+tweak(int *ip, int i, int min, int max) {
+	if(!lt[sellt]->arrange)
 		return;
-	*var = i;
+	if(i < min)
+		i = min;
+	else if(i > max)
+		i = max;
+	*ip = i;
 	arrange();
 }
 
 void
 tweakmn(const Arg *arg) {
-	tweak(&mn, arg->v, 1, wh / (1 + 2 * borderpx));
+	int *a = arg->v;
+
+	tweak(&mn, a[0] * mn + a[1], 1, wh / (1 + 2 * borderpx));
 }
 
 void
 tweakmwp(const Arg *arg) {
-	tweak(&mwp, arg->v, 5, 95);
+	int *a = arg->v;
+
+	tweak(&mwp, a[0] * mwp + a[1], 5, 100);
 }
 
 void