diff --git a/packages/rgbds/build.sh b/packages/rgbds/build.sh
index c7a1a15143..d44ef62b94 100644
--- a/packages/rgbds/build.sh
+++ b/packages/rgbds/build.sh
@@ -2,7 +2,7 @@ TERMUX_PKG_HOMEPAGE=https://rgbds.gbdev.io
 TERMUX_PKG_DESCRIPTION="Rednex Game Boy Development System - An assembly toolchain for the Nintendo Game Boy & Game Boy Color"
 TERMUX_PKG_LICENSE="MIT"
 TERMUX_PKG_MAINTAINER="@termux"
-TERMUX_PKG_VERSION=0.5.0
+TERMUX_PKG_VERSION=0.5.1
 TERMUX_PKG_SRCURL=https://github.com/gbdev/rgbds/releases/download/v${TERMUX_PKG_VERSION}/rgbds-${TERMUX_PKG_VERSION}.tar.gz
-TERMUX_PKG_SHA256=56708515afafa8bf6e8e5aec398d23484859008da5714d2c160107626142964b
+TERMUX_PKG_SHA256=e42a4b6a7f45e5e6ebc56c513f5607c6adcccb1b7f44c0cb35fef428ed9cbe8c
 TERMUX_PKG_DEPENDS="libpng"
diff --git a/packages/rgbds/src-extern-getopt.c.patch b/packages/rgbds/src-extern-getopt.c.patch
index 1eac692a70..92ef510c3d 100644
--- a/packages/rgbds/src-extern-getopt.c.patch
+++ b/packages/rgbds/src-extern-getopt.c.patch
@@ -2,11 +2,11 @@ diff -uNr rgbds/src/extern/getopt.c rgbds.mod/src/extern/getopt.c
 --- rgbds/src/extern/getopt.c	2021-03-20 00:41:50.000000000 +0000
 +++ rgbds.mod/src/extern/getopt.c	2021-05-05 14:58:53.925498951 +0000
 @@ -208,7 +208,7 @@
- 			}
- 			cnt++;
- 		}
--		if (cnt == 1 && longonly && arg - start == mblen(start, MB_LEN_MAX)) {
-+		if (cnt == 1 && longonly && arg - start == mbtowc(0, start, MB_LEN_MAX)) {
- 			int l = arg - start;
- 
- 			for (i = 0; optstring[i]; i++) {
+ 			}
+ 			cnt++;
+ 		}
+-		if (cnt == 1 && longonly && arg - start == mblen(start, MB_LEN_MAX)) {
++		if (cnt == 1 && longonly && arg - start == mbtowc(0, start, MB_LEN_MAX)) {
+ 			int l = arg - start;
+ 
+ 			for (i = 0; optstring[i]; i++) {