diff --git a/config.h b/config.h
index 771e7a1..6c880c2 100644
--- a/config.h
+++ b/config.h
@@ -45,12 +45,12 @@ static const Rule rules[] = {
 	 *	WM_CLASS(STRING) = instance, class
 	 *	WM_NAME(STRING) = title
 	*/
-	/* class    instance      title       	 tags mask    isfloating   isterminal  noswallow  monitor */
-	{ "Gimp",     NULL,       NULL,       	    1 << 8,       0,           0,         0,        -1 },
-	{ "St",       NULL,       NULL,       	    0,            0,           1,         0,        -1 },
-	{ NULL,       NULL,       "Event Tester",   0,            0,           0,         1,        -1 },
-	{ NULL,      "spterm",    NULL,       	    SPTAG(0),     1,           1,         0,        -1 },
-	{ NULL,      "spcalc",    NULL,       	    SPTAG(1),     1,           1,         0,        -1 },
+	/* class    instance      title       	 tags mask    iscentered  isfloating   isterminal  noswallow  monitor */
+	{ "Gimp",     NULL,       NULL,       	    1 << 8,       0,          0,           0,         0,        -1 },
+	{ "St",       NULL,       NULL,       	    0,            0,          0,           1,         0,        -1 },
+	{ NULL,       NULL,       "Event Tester",   0,            0,          0,           0,         1,        -1 },
+	{ NULL,      "spterm",    NULL,       	    SPTAG(0),     0,          1,           1,         0,        -1 },
+	{ NULL,      "spcalc",    NULL,       	    SPTAG(1),     0,          1,           1,         0,        -1 },
 };
 
 /* layout(s) */
diff --git a/dwm.c b/dwm.c
index 2e43282..4220f87 100644
--- a/dwm.c
+++ b/dwm.c
@@ -119,7 +119,7 @@ struct Client {
 	int basew, baseh, incw, inch, maxw, maxh, minw, minh;
 	int bw, oldbw;
 	unsigned int tags;
-	int isfixed, isfloating, isurgent, neverfocus, oldstate, isfullscreen, isterminal, noswallow, issticky;
+	int isfixed, iscentered, isfloating, isurgent, neverfocus, oldstate, isfullscreen, isterminal, noswallow, issticky;
 	pid_t pid;
 	Client *next;
 	Client *snext;
@@ -170,6 +170,7 @@ typedef struct {
 	const char *instance;
 	const char *title;
 	unsigned int tags;
+	int iscentered;
 	int isfloating;
 	int isterminal;
 	int noswallow;
@@ -348,6 +349,7 @@ applyrules(Client *c)
 	XClassHint ch = { NULL, NULL };
 
 	/* rule matching */
+	c->iscentered = 0;
 	c->isfloating = 0;
 	c->tags = 0;
 	XGetClassHint(dpy, c->win, &ch);
@@ -361,6 +363,7 @@ applyrules(Client *c)
 		&& (!r->instance || strstr(instance, r->instance)))
 		{
 			c->isterminal = r->isterminal;
+			c->iscentered = r->iscentered;
 			c->isfloating = r->isfloating;
 			c->noswallow  = r->noswallow;
 			c->tags |= r->tags;
@@ -1250,6 +1253,10 @@ manage(Window w, XWindowAttributes *wa)
 	updatewindowtype(c);
 	updatesizehints(c);
 	updatewmhints(c);
+	if (c->iscentered) {
+		c->x = c->mon->mx + (c->mon->mw - WIDTH(c)) / 2;
+		c->y = c->mon->my + (c->mon->mh - HEIGHT(c)) / 2;
+	}
 	XSelectInput(dpy, w, EnterWindowMask|FocusChangeMask|PropertyChangeMask|StructureNotifyMask);
 	grabbuttons(c, 0);
 	if (!c->isfloating)
@@ -2339,8 +2346,10 @@ updatewindowtype(Client *c)
 
 	if (state == netatom[NetWMFullscreen])
 		setfullscreen(c, 1);
-	if (wtype == netatom[NetWMWindowTypeDialog])
+	if (wtype == netatom[NetWMWindowTypeDialog]) {
+		c->iscentered = 1;
 		c->isfloating = 1;
+	}
 }
 
 void