diff --git a/README.md b/README.md
index 7f5d266..f201195 100644
--- a/README.md
+++ b/README.md
@@ -15,7 +15,7 @@ Refer to [https://st.suckless.org/](https://st.suckless.org/) for details on the
 
 ### Changelog:
 
-2021-05-09 - Added the sync patch
+2021-05-09 - Added the sync and alpha-focus-hightlight patches
 
 2021-05-08 - Added blinking cursor, delkey, undercurl,universcroll, desktopentry, netwmicon and osc_10_11_12_2 patches
 
@@ -68,6 +68,10 @@ Refer to [https://st.suckless.org/](https://st.suckless.org/) for details on the
    - [alpha](https://st.suckless.org/patches/alpha/)
       - adds transparency for the terminal
 
+   - [alpha-focus-highlight](https://st.suckless.org/patches/alpha_focus_highlight/)
+      - allows the user to specify two distinct opacity values or background colors in order to
+        easily differentiate between focused and unfocused terminal windows
+
    - [anysize](https://st.suckless.org/patches/anysize/)
       - allows st to reize to any pixel size rather than snapping to character width / height
 
diff --git a/config.def.h b/config.def.h
index c6d37bd..68831fa 100644
--- a/config.def.h
+++ b/config.def.h
@@ -140,6 +140,9 @@ float alpha = 0.8;
 float grad_alpha = 0.54; //alpha value that'll change
 float stat_alpha = 0.46; //constant alpha value that'll get added to grad_alpha
 #endif // ALPHA_GRADIENT_PATCH
+#if ALPHA_FOCUS_HIGHLIGHT_PATCH
+float alphaUnfocused = 0.6;
+#endif // ALPHA_FOCUS_HIGHLIGHT_PATCH
 #endif // ALPHA_PATCH
 
 /* Terminal colors (16 first used in escape sequence) */
@@ -178,8 +181,13 @@ static const char *colorname[] = {
  * Default colors (colorname index)
  * foreground, background, cursor, reverse cursor
  */
-unsigned int defaultfg = 259;
+#if ALPHA_PATCH && ALPHA_FOCUS_HIGHLIGHT_PATCH
+unsigned int defaultbg = 0;
+unsigned int bg = 17, bgUnfocused = 16;
+#else
 unsigned int defaultbg = 258;
+#endif // ALPHA_FOCUS_HIGHLIGHT_PATCH
+unsigned int defaultfg = 259;
 unsigned int defaultcs = 256;
 unsigned int defaultrcs = 257;
 
diff --git a/patches.def.h b/patches.def.h
index e2b2a05..b327803 100644
--- a/patches.def.h
+++ b/patches.def.h
@@ -16,6 +16,14 @@
  */
 #define ALPHA_PATCH 0
 
+/* The alpha focus highlight patch allows the user to specify two distinct opacity values or
+ * background colors in order to easily differentiate between focused and unfocused terminal
+ * windows. This depends on the alpha patch.
+ * https://github.com/juliusHuelsmann/st-focus/
+ * https://st.suckless.org/patches/alpha_focus_highlight/
+ */
+#define ALPHA_FOCUS_HIGHLIGHT_PATCH 0
+
 /* Adds gradient transparency to st, depends on the alpha patch.
  * https://st.suckless.org/patches/gradient/
  */
diff --git a/st.h b/st.h
index c4d99c9..0c2f960 100644
--- a/st.h
+++ b/st.h
@@ -343,6 +343,9 @@ extern const int boxdraw, boxdraw_bold, boxdraw_braille;
 #endif // BOXDRAW_PATCH
 #if ALPHA_PATCH
 extern float alpha;
+#if ALPHA_FOCUS_HIGHLIGHT_PATCH
+extern float alphaUnfocused;
+#endif // ALPHA_FOCUS_HIGHLIGHT_PATCH
 #endif // ALPHA_PATCH
 
 extern DC dc;
diff --git a/x.c b/x.c
index b0b7709..fa4a8fa 100644
--- a/x.c
+++ b/x.c
@@ -185,6 +185,10 @@ static char *opt_title = NULL;
 static char *opt_dir   = NULL;
 #endif // WORKINGDIR_PATCH
 
+#if ALPHA_PATCH && ALPHA_FOCUS_HIGHLIGHT_PATCH
+static int focused = 0;
+#endif // ALPHA_FOCUS_HIGHLIGHT_PATCH
+
 static int oldbutton = 3; /* button event on startup: 3 = release */
 #if BLINKING_CURSOR_PATCH
 static int cursorblinks = 0;
@@ -772,6 +776,44 @@ xloadcolor(int i, const char *name, Color *ncolor)
 	return XftColorAllocName(xw.dpy, xw.vis, xw.cmap, name, ncolor);
 }
 
+#if ALPHA_PATCH && ALPHA_FOCUS_HIGHLIGHT_PATCH
+void
+xloadalpha(void)
+{
+	float const usedAlpha = focused ? alpha : alphaUnfocused;
+	if (opt_alpha) alpha = strtof(opt_alpha, NULL);
+	dc.col[defaultbg].color.alpha = (unsigned short)(0xffff * usedAlpha);
+	dc.col[defaultbg].pixel &= 0x00FFFFFF;
+	dc.col[defaultbg].pixel |= (unsigned char)(0xff * usedAlpha) << 24;
+}
+#endif // ALPHA_FOCUS_HIGHLIGHT_PATCH
+
+#if ALPHA_PATCH && ALPHA_FOCUS_HIGHLIGHT_PATCH
+void
+xloadcols(void)
+{
+	static int loaded;
+	Color *cp;
+
+	if (!loaded) {
+		dc.collen = 1 + (defaultbg = MAX(LEN(colorname), 256));
+		dc.col = xmalloc((dc.collen) * sizeof(Color));
+	}
+
+	for (int i = 0; i+1 < dc.collen; ++i)
+		if (!xloadcolor(i, NULL, &dc.col[i])) {
+			if (colorname[i])
+				die("could not allocate color '%s'\n", colorname[i]);
+			else
+				die("could not allocate color %d\n", i);
+		}
+	if (dc.collen) // cannot die, as the color is already loaded.
+		xloadcolor(focused ? bg : bgUnfocused, NULL, &dc.col[defaultbg]);
+
+	xloadalpha();
+	loaded = 1;
+}
+#else
 void
 xloadcols(void)
 {
@@ -804,6 +846,7 @@ xloadcols(void)
 	#endif // ALPHA_PATCH
 	loaded = 1;
 }
+#endif // ALPHA_FOCUS_HIGHLIGHT_PATCH
 
 int
 xsetcolorname(int x, const char *name)
@@ -2344,12 +2387,26 @@ focus(XEvent *ev)
 		xseturgency(0);
 		if (IS_SET(MODE_FOCUS))
 			ttywrite("\033[I", 3, 0);
+		#if ALPHA_PATCH && ALPHA_FOCUS_HIGHLIGHT_PATCH
+		if (!focused) {
+			focused = 1;
+			xloadcols();
+			redraw();
+		}
+		#endif // ALPHA_FOCUS_HIGHLIGHT_PATCH
 	} else {
 		if (xw.ime.xic)
 			XUnsetICFocus(xw.ime.xic);
 		win.mode &= ~MODE_FOCUSED;
 		if (IS_SET(MODE_FOCUS))
 			ttywrite("\033[O", 3, 0);
+		#if ALPHA_PATCH && ALPHA_FOCUS_HIGHLIGHT_PATCH
+		if (focused) {
+			focused = 0;
+			xloadcols();
+			redraw();
+		}
+		#endif // ALPHA_FOCUS_HIGHLIGHT_PATCH
 	}
 }
 
@@ -2771,6 +2828,9 @@ run:
 	#endif // XRESOURCES_RELOAD_PATCH
 	cols = MAX(cols, 1);
 	rows = MAX(rows, 1);
+	#if ALPHA_PATCH && ALPHA_FOCUS_HIGHLIGHT_PATCH
+	defaultbg = MAX(LEN(colorname), 256);
+	#endif // ALPHA_FOCUS_HIGHLIGHT_PATCH
 	tnew(cols, rows);
 	xinit(cols, rows);
 	xsetenv();