diff --git a/math/gh-bc/Makefile b/math/gh-bc/Makefile
index 606f7db891b45..91e6d0f564344 100644
--- a/math/gh-bc/Makefile
+++ b/math/gh-bc/Makefile
@@ -1,5 +1,5 @@
 PORTNAME=	bc
-PORTVERSION=	4.0.2
+PORTVERSION=	5.0.0
 CATEGORIES=	math lang
 PKGNAMEPREFIX=	gh-
 
@@ -10,21 +10,22 @@ LICENSE=	BSD2CLAUSE MIT
 LICENSE_COMB=	multi
 LICENSE_FILE=	${WRKSRC}/LICENSE.md
 
-USES=		compiler
+USES=		compiler:c11
 USE_GITHUB=	yes
 GH_ACCOUNT=	gavinhoward
 
-HAS_CONFIGURE=	yes
+HAS_CONFIGURE=		yes
 CONFIGURE_SCRIPT=	configure.sh
-CONFIGURE_ARGS=	-G
+CONFIGURE_ARGS=		-G
+CFLAGS+=		-Dstatic_assert=_Static_assert
 
 .include <bsd.port.pre.mk>
 
-.if ${CHOSEN_COMPILER_TYPE} == gcc && ${COMPILER_VERSION} <= 42
-CFLAGS+=	--std=c99
-.endif
+#.if ${CHOSEN_COMPILER_TYPE} == gcc && ${COMPILER_VERSION} <= 42
+#CFLAGS+=	--std=c99
+#.endif
 
-CONFLICTS_INSTALL=	gnubc-[0-9]*
+CONFLICTS_INSTALL=	gnubc
 
 pre-build:
 		${INSTALL_SCRIPT} ${WRKSRC}/gen/strgen.sh ${WRKSRC}/gen/strgen
@@ -35,7 +36,7 @@ do-install:
 		${INSTALL_MAN} ${WRKSRC}/manuals/bc.1 ${STAGEDIR}${MANPREFIX}/share/man/man1
 		${INSTALL_MAN} ${WRKSRC}/manuals/dc.1 ${STAGEDIR}${MANPREFIX}/share/man/man1
 		${MKDIR} ${STAGEDIR}${PREFIX}/share/nls/C
-		${WRKSRC}/locale_install.sh ${STAGEDIR}${PREFIX}/share/nls/%L/%N.cat ${PORTNAME}
+		${WRKSRC}/scripts/locale_install.sh ${STAGEDIR}${PREFIX}/share/nls/%L/%N.cat ${PORTNAME}
 		${MV} ${STAGEDIR}${PREFIX}/share/nls/en_US/bc.cat ${STAGEDIR}${PREFIX}/share/nls/C/
 		${RMDIR} ${STAGEDIR}${PREFIX}/share/nls/en_US
 
diff --git a/math/gh-bc/distinfo b/math/gh-bc/distinfo
index 6fa2323998001..e559bace8f830 100644
--- a/math/gh-bc/distinfo
+++ b/math/gh-bc/distinfo
@@ -1,3 +1,3 @@
-TIMESTAMP = 1620795472
-SHA256 (gavinhoward-bc-4.0.2_GH0.tar.gz) = f940483d09087746b2da56000e406320a2a7e9ba7d61920621b33bd7981fa151
-SIZE (gavinhoward-bc-4.0.2_GH0.tar.gz) = 1139323
+TIMESTAMP = 1628528378
+SHA256 (gavinhoward-bc-5.0.0_GH0.tar.gz) = 3b25215f5e6ceb8c073f5486473d6542fe6d76c580f3e7a343cefc58a8dfc0ea
+SIZE (gavinhoward-bc-5.0.0_GH0.tar.gz) = 1164772
diff --git a/math/gh-bc/files/patch-locale__install.sh b/math/gh-bc/files/patch-locale__install.sh
deleted file mode 100644
index ce93b44a77bce..0000000000000
--- a/math/gh-bc/files/patch-locale__install.sh
+++ /dev/null
@@ -1,27 +0,0 @@
---- locale_install.sh.orig	2020-11-26 16:00:16 UTC
-+++ locale_install.sh
-@@ -211,6 +211,7 @@ for file in $locales_dir/*.msg; do
- 
- 	loc=$(gen_nlspath "$destdir/$nlspath" "$locale" "$main_exec")
- 
-+	echo gencatfile "$loc" "$file"
- 	gencatfile "$loc" "$file"
- 
- done
-@@ -239,14 +240,13 @@ for file in $locales_dir/*.msg; do
- 		linkdir=$(dirname "$file")
- 		locale=$(basename "$link" .msg)
- 		linksrc=$(gen_nlspath "$nlspath" "$locale" "$main_exec")
--		relloc="${loc##$destdir/}"
--		rel=$(relpath "$linksrc" "$relloc")
- 
- 		if [ ! -f "$destdir/$linksrc" ]; then
- 			gencatfile "$destdir/$linksrc" "$linkdir/$link"
- 		fi
- 
--		ln -fs "$rel" "$loc"
-+		echo ln "$linksrc" "$loc"
-+		ln "$linksrc" "$loc"
- 	fi
- 
- done
diff --git a/math/gh-bc/files/patch-scripts_locale__install.sh b/math/gh-bc/files/patch-scripts_locale__install.sh
new file mode 100644
index 0000000000000..4d452bd0b101a
--- /dev/null
+++ b/math/gh-bc/files/patch-scripts_locale__install.sh
@@ -0,0 +1,29 @@
+--- scripts/locale_install.sh.orig	2021-06-28 18:10:45 UTC
++++ scripts/locale_install.sh
+@@ -243,6 +243,7 @@ for file in $locales_dir/*.msg; do
+ 	# Generate the proper location for the cat file.
+ 	loc=$(gen_nlspath "$destdir/$nlspath" "$locale" "$main_exec")
+ 
++	echo gencatfile "$loc" "$file"
+ 	gencatfile "$loc" "$file"
+ 
+ done
+@@ -282,8 +283,6 @@ for file in $locales_dir/*.msg; do
+ 		linkdir=$(dirname "$file")
+ 		locale=$(basename "$link" .msg)
+ 		linksrc=$(gen_nlspath "$nlspath" "$locale" "$main_exec")
+-		relloc="${loc##$destdir/}"
+-		rel=$(relpath "$linksrc" "$relloc")
+ 
+ 		# If the target file doesn't exist (because it's for a locale that is
+ 		# not installed), generate it anyway. It's easier this way.
+@@ -293,7 +292,8 @@ for file in $locales_dir/*.msg; do
+ 
+ 		# Finally, symlink to the install of the generated cat file that
+ 		# corresponds to the correct msg file.
+-		ln -fs "$rel" "$loc"
++		echo ln "$linksrc" "$loc"
++		ln "$linksrc" "$loc"
+ 	fi
+ 
+ done