diff --git a/testing/9base/APKBUILD b/testing/9base/APKBUILD
index 1cb53d3d70e1b54c5002c77a896c5be0b2c50a11..9d77b93e468b520ea724650e2d6a95d74bfe594a 100644
--- a/testing/9base/APKBUILD
+++ b/testing/9base/APKBUILD
@@ -15,8 +15,13 @@ source="https://dl.suckless.org/tools/9base-$pkgver.tar.gz
 	config.mk.i686
 	config.mk.s390x
 	config.mk.ppc64le
+	config.mk.riscv64
 	dirread.patch
-	s390x.patch"
+	s390x.patch
+	riscv64.patch"
+
+# Fix build with gcc >= 10, too many definitions affected.
+export CFLAGS="$CFLAGS -fcommon"
 
 prepare() {
 	default_prepare
@@ -46,10 +51,14 @@ troff() {
 	mv "$pkgdir/usr/lib/9base/lib/troff" "$subpkgdir/usr/lib/9base/lib/troff"
 }
 
-sha512sums="38108a94118b56c6f3982e692beb1068c52f9aecd74447d6b552b77fae5e365eab72b4781bdf07d9696ac89d54371c1cae8cc0363de510b53988302acef50dba  9base-6.tar.gz
+sha512sums="
+38108a94118b56c6f3982e692beb1068c52f9aecd74447d6b552b77fae5e365eab72b4781bdf07d9696ac89d54371c1cae8cc0363de510b53988302acef50dba  9base-6.tar.gz
 3a30955d59ad78c1bc4e2fbd0f511eb85624ed48b0aeceef436e3456f685690e064eb1f171a2080a34a0fcb40d874277a282864c720c9e612eca3ad848dec35e  config.mk.x86_64
 7a58d4762c5ec9a0191f2cce15b23b2e60ec9445c357dc2e3925a5b4d5dec1c5eed6fb3565be07a25616c0c2b0768c21737b2d35082deb17bfc7a7f5f0c0d2a6  config.mk.i686
 61e67a22abf8f7d3dbfadda92cf0836e8726ae8225939318d0bf34dc05b47a12dd41de895f7b5df515ba5cd783dae368cce98706366cc28360a1987b4e7c652c  config.mk.s390x
 dd0f9ff55e103fd16f689f01e41769cf6bc6370201e790bf64236570cda2d0e6ef2954f1b5798feb4ebd65fc1a0563ce71c8a9b7fb05166a8ff28ac8be472dfe  config.mk.ppc64le
+d832d40601687068ac5c558db4e2d52cff25a0c7a04d0de0d2d4987015e60a0c3b9da8dc9f47e836ed2ee77fda991111a0a2039007d7803e85d6d62885d835c3  config.mk.riscv64
 5b47647245366e786059a28747fe9a36fd87d9df2e1a7f68e9a41f4adb7ec96f230a9abe94acbe5f82d62f4f85b061ff7ab7356d32072dd9ef7f677379f456f5  dirread.patch
-f1f05e2a6081f2a451256de9af669e1ff1e82b6603b376677825421c11bd6ef22a8ab0eb89c15b0589252bada71b58214b6306127bdd379952203105f14e49e9  s390x.patch"
+f1f05e2a6081f2a451256de9af669e1ff1e82b6603b376677825421c11bd6ef22a8ab0eb89c15b0589252bada71b58214b6306127bdd379952203105f14e49e9  s390x.patch
+aec441bd768a969ff11774be6bf85413b61f45b9967f7720b7e8b5ef75ae6f834cf8f40177114c337c95e33f0b5a717685b54cd8a43b953cd2301616241abf33  riscv64.patch
+"
diff --git a/testing/9base/config.mk.riscv64 b/testing/9base/config.mk.riscv64
new file mode 100644
index 0000000000000000000000000000000000000000..6f61bb021100faa8bbf81dcda15ee3a1873e2f08
--- /dev/null
+++ b/testing/9base/config.mk.riscv64
@@ -0,0 +1,24 @@
+# Customize to fit your system
+
+# paths
+PREFIX      = /usr/lib/9base
+MANPREFIX   = ${PREFIX}/share/man
+
+VERSION     = 6
+#OBJTYPE     = 386
+#OBJTYPE     = arm
+OBJTYPE     = riscv64
+
+# Linux/BSD
+#CFLAGS      += -Wall -Wno-missing-braces -Wno-parentheses -Wno-switch -c -I. -DPREFIX="\"${PREFIX}\""
+CFLAGS      += -c -I. -DPREFIX="\"${PREFIX}\""
+LDFLAGS     += -static
+
+# Solaris
+#CFLAGS      = -fast -xtarget=ultra -D__sun__ -c -I. -DPREFIX="\"${PREFIX}\""
+#LDFLAGS     = -dn
+
+# compiler
+AR          = ar rc
+CC          = cc
+YACC        = ../yacc/9yacc
diff --git a/testing/9base/riscv64.patch b/testing/9base/riscv64.patch
new file mode 100644
index 0000000000000000000000000000000000000000..24e83eb7ba3656843c62918eeaa6c9e39975edeb
--- /dev/null
+++ b/testing/9base/riscv64.patch
@@ -0,0 +1,13 @@
+Taken from the posix-riscv64 subdirectory in the community/drawterm source.
+
+diff -uNr 9base-6-orig/lib9/getcallerpc-riscv64.c 9base-6/lib9/getcallerpc-riscv64.c
+--- 9base-6-orig/lib9/getcallerpc-riscv64.c	1970-01-01 01:00:00.000000000 +0100
++++ 9base-6/lib9/getcallerpc-riscv64.c	2021-07-04 16:39:04.452113924 +0200
+@@ -0,0 +1,7 @@
++#include <lib9.h>
++
++ulong
++getcallerpc(void *x)
++{
++	return ((uintptr*)x)[-1];
++}