diff --git a/layouts/tile.c b/layouts/tile.c
index cb138785c..a25a27505 100644
--- a/layouts/tile.c
+++ b/layouts/tile.c
@@ -42,23 +42,17 @@ uicb_setnmaster(Display *disp,
                 awesome_config *awesomeconf,
                 const char * arg)
 {
-    int delta;
-    int wah = get_windows_area_height(disp, awesomeconf->statusbar);
-
     if(!IS_ARRANGE(tile) && !IS_ARRANGE(tileleft) && !IS_ARRANGE(bstack) && !IS_ARRANGE(bstackportrait))
         return;
+
     if(!arg)
         nmaster = awesomeconf->nmaster;
-    else if(sscanf(arg, "%d", &delta))
-    {
-        if((arg[0] == '+' || arg[0] == '-')
-           && !((nmaster + delta) < 1 || wah / (nmaster + delta) <= 2 * awesomeconf->borderpx))
-            nmaster += delta;
-        else if(delta >= 1 && wah / delta <= 2 * awesomeconf->borderpx)
-            nmaster = delta;
-        else
-            return;
-    }
+    else
+        nmaster = (int) compute_new_value_from_arg(arg, (double) nmaster);
+
+    if(nmaster < 1)
+        nmaster = 1;
+
     if(sel)
         arrange(disp, drawcontext, awesomeconf);
     else
diff --git a/util.c b/util.c
index 3250e9061..b247b7e16 100644
--- a/util.c
+++ b/util.c
@@ -102,3 +102,19 @@ xgettextprop(Display *disp, Window w, Atom atom, char *text, unsigned int size)
 
     return True;
 }
+
+double
+compute_new_value_from_arg(const char *arg, double current_value)
+{
+    double delta;
+
+    if(arg && sscanf(arg, "%lf", &delta) == 1)
+    {
+        if(arg[0] == '+' || arg[0] == '-')
+            current_value += delta;
+        else
+            current_value = delta;
+    }
+
+    return current_value;
+}
diff --git a/util.h b/util.h
index e957a5967..c73a59b14 100644
--- a/util.h
+++ b/util.h
@@ -121,5 +121,6 @@ static inline char *a_strdup(const char *s)
 void eprint(const char *, ...) __attribute__ ((noreturn)) __attribute__ ((format(printf, 1, 2)));
 void uicb_spawn(Display *, DC *, awesome_config *, const char *);
 Bool xgettextprop(Display *, Window, Atom, char *, unsigned int);
+double compute_new_value_from_arg(const char *, double);
 
 #endif