diff --git a/config.def.h b/config.def.h
index 91ab8ca..8a06176 100644
--- a/config.def.h
+++ b/config.def.h
@@ -93,6 +93,9 @@ char *termname = "st-256color";
  */
 unsigned int tabspaces = 8;
 
+/* Background opacity */
+float alpha_def;
+
 /* Terminal colors (16 first used in escape sequence) */
 static const char *colorname[] = {
 	/* 8 normal colors */
@@ -201,6 +204,9 @@ static Shortcut shortcuts[] = {
 	{ TERMMOD,              XK_Y,           selpaste,       {.i =  0} },
 	{ ShiftMask,            XK_Insert,      selpaste,       {.i =  0} },
 	{ TERMMOD,              XK_Num_Lock,    numlock,        {.i =  0} },
+	{ MODKEY,               XK_bracketleft, chgalpha,       {.f = -1} }, /* Decrease opacity */
+	{ MODKEY|ShiftMask,     XK_braceright,  chgalpha,       {.f = +1} }, /* Increase opacity */
+	{ MODKEY,               XK_bracketright,chgalpha,       {.f =  0} }, /* Reset opacity */
 };
 
 /*
diff --git a/st.h b/st.h
index fd3b0d8..3bb587e 100644
--- a/st.h
+++ b/st.h
@@ -124,3 +124,4 @@ extern unsigned int tabspaces;
 extern unsigned int defaultfg;
 extern unsigned int defaultbg;
 extern unsigned int defaultcs;
+extern float alpha_def;
diff --git a/x.c b/x.c
index aa09997..f8c8c1a 100644
--- a/x.c
+++ b/x.c
@@ -59,6 +59,7 @@ static void zoom(const Arg *);
 static void zoomabs(const Arg *);
 static void zoomreset(const Arg *);
 static void ttysend(const Arg *);
+static void chgalpha(const Arg *);
 
 /* config.h for applying patches and the configuration. */
 #include "config.h"
@@ -1147,6 +1148,9 @@ xinit(int cols, int rows)
 	usedfont = (opt_font == NULL)? font : opt_font;
 	xloadfonts(usedfont, 0);
 
+   /* Backup default alpha value */
+   alpha_def = alpha;
+
 	/* colors */
 	xw.cmap = XDefaultColormap(xw.dpy, xw.scr);
 	xloadcols();
@@ -1371,6 +1375,24 @@ xmakeglyphfontspecs(XftGlyphFontSpec *specs, const Glyph *glyphs, int len, int x
 	return numspecs;
 }
 
+void
+chgalpha(const Arg *arg)
+{
+   if (arg->f == -1.0f && alpha >= 0.1f)
+      alpha -= 0.1f;
+   else if (arg->f == 1.0f && alpha < 1.0f)
+      alpha += 0.1f;
+   else if (arg->f == 0.0f)
+      alpha = alpha_def;
+   else
+      return;
+
+   dc.col[defaultbg].color.alpha = (unsigned short)(0xFFFF * alpha);
+   /* Required to remove artifacting from borderpx */
+   cresize(0, 0);
+   redraw();
+}
+
 void
 xdrawglyphfontspecs(const XftGlyphFontSpec *specs, Glyph base, int len, int x, int y)
 {