diff --git a/config.h b/config.h
index bfe4c87..8a8fba2 100644
--- a/config.h
+++ b/config.h
@@ -8,6 +8,7 @@ static const int showbar            = 1;        /* 0 means no bar */
 static const int topbar             = 1;        /* 0 means bottom bar */
 static const int vertpad            = 10;       /* vertical padding of bar */
 static const int sidepad            = 20;       /* horizontal padding of bar */
+static const float firstwindowoffset = 0.1;	/* render first window 10% larger than mfact would for firstwindowcentered layout */
 static const char *fonts[]          = { "monospace:size=13",
 					"IPAGothic:size=13",
 					"symbola:size=13"};
diff --git a/dwm.c b/dwm.c
index 95d0de1..16ccafb 100644
--- a/dwm.c
+++ b/dwm.c
@@ -17,7 +17,6 @@
  * client.
  *
  * Keys and tagging rules are organized as arrays and defined in config.h.
- *
  * To understand everything else, start reading main().
  */
 #include <errno.h>
@@ -2507,10 +2506,10 @@ centeredfirstwindow(Monitor *m)
 
 	/* initialize nmaster area */
 	if (m->ww > m->wh) {
-		mw = m->nmaster ? m->ww * m->mfact : 0;
+		mw = m->nmaster ? m->ww * (m->mfact + firstwindowoffset) : 0;
 		mh = m->nmaster ? m->wh : 0;
 	} else {
-		mh = m->nmaster ? m->wh * m->mfact : 0;
+		mh = m->nmaster ? m->wh * (m->mfact + firstwindowoffset) : 0;
 		mw = m->nmaster ? m->ww : 0;
 	}
 	mx = mxo = (m->ww - mw) / 2;