diff --git a/parts.rst b/parts.rst
index 13fa0de..e28e6f9 100644
--- a/parts.rst
+++ b/parts.rst
@@ -114,7 +114,7 @@ which we extract and then build.
 
 Going forward, we can now use ``.tar.gz`` for source code.
 
-sed 4.0.7
+sed 4.0.9
 =========
 
 You are most likely aware of GNU ``sed``, a line editor.
@@ -252,7 +252,7 @@ uses floats extensively.
 sed 4.0.9
 =========
 
-A slightly newer ``sed`` is built against musl.
+``sed`` is rebuilt against musl.
 
 bzip2 1.0.8
 ===========
diff --git a/rootfs.sh b/rootfs.sh
index 7abaa55..dea8213 100755
--- a/rootfs.sh
+++ b/rootfs.sh
@@ -138,8 +138,8 @@ get_file() {
 # gzip 1.2.4
 get_file https://ftp.gnu.org/gnu/gzip/gzip-1.2.4.tar 1
 
-# sed 4.0.7
-get_file https://ftp.gnu.org/gnu/sed/sed-4.0.7.tar.gz 1
+# sed 4.0.9
+get_file https://ftp.gnu.org/gnu/sed/sed-4.0.9.tar.gz 1
 
 # patch 2.5.9
 get_file https://ftp.gnu.org/pub/gnu/patch/patch-2.5.9.tar.gz 1
@@ -168,9 +168,6 @@ get_file http://download.nust.na/pub2/openpkg1/sources/DST/flex/flex-2.5.11.tar.
 # musl 1.1.24
 get_file https://musl.libc.org/releases/musl-1.1.24.tar.gz
 
-# sed 4.0.9
-get_file https://ftp.gnu.org/gnu/sed/sed-4.0.9.tar.gz
-
 # m4 1.4.7
 get_file https://ftp.gnu.org/gnu/m4/m4-1.4.7.tar.gz
 
diff --git a/sysa/after.kaem.run b/sysa/after.kaem.run
index 4d7e28c..c619363 100755
--- a/sysa/after.kaem.run
+++ b/sysa/after.kaem.run
@@ -69,7 +69,7 @@ kaem --file ${pkg}.kaem
 cd ..
 
 # sed
-pkg="sed-4.0.7"
+pkg="sed-4.0.9"
 cd ${pkg}
 kaem --file ${pkg}.kaem
 cd ..
diff --git a/sysa/helpers.sh b/sysa/helpers.sh
index e652358..68f5f70 100755
--- a/sysa/helpers.sh
+++ b/sysa/helpers.sh
@@ -2,6 +2,7 @@
 
 # SPDX-FileCopyrightText: 2021 Andrius Štikonas <andrius@stikonas.eu>
 # SPDX-FileCopyrightText: 2021 fosslinux <fosslinux@aussies.space>
+# SPDX-FileCopyrightText: 2021 Paul Dersey <pdersey@gmail.com>
 #
 # SPDX-License-Identifier: GPL-3.0-or-later
 
@@ -69,13 +70,14 @@ build () {
 default_src_unpack() {
     src_dir="${base_dir}/src"
 
-    for suf in gz bz2 xz; do
-        source="${src_dir}/${pkg}.tar.${suf}"
+    for suf in .gz .bz2 .xz ""; do
+        source="${src_dir}/${pkg}.tar${suf}"
         if test -e "${source}"; then
             case "${suf}" in
-                gz) tar -xzf "${source}" ;;
-                bz2) tar -xf "${source}" --use-compress-program=bzip2 ;;
-                xz) tar -xf "${source}" --use-compress-program=xz ;;
+                .gz) tar -xzf "${source}" ;;
+                .bz2) tar -xf "${source}" --use-compress-program=bzip2 ;;
+                .xz) tar -xf "${source}" --use-compress-program=xz ;;
+                "") tar -xf "${source}" ;;
             esac
         fi
     done
diff --git a/sysa/pre-sha.sha256sums b/sysa/pre-sha.sha256sums
index 1e310c5..736f9ef 100644
--- a/sysa/pre-sha.sha256sums
+++ b/sysa/pre-sha.sha256sums
@@ -13,7 +13,7 @@ d41067670562f87c6e43af0b461c4070c19a8ffc15c455cb075d98419ae76c73  /after/bin/mes
 b91c81e543b878ead4cc975df75e3d211f7bd2dcdd4c90e42df99d44311ce71e  /after/bin/mescc.scm
 e94a2468c045582cfd13df51acd0932afdc834fa60139f7bfb7a2d65afa39a65  /after/bin/mes-tcc
 3cf426251744300a099a40f3609ccbd32ec3b9f3334601defa5736e7fd6c6f1d  /after/bin/patch
-b4b16b3314a6f4a8be1b849aba45252e621a7123025dabdf9af6c2d4d657e9b6  /after/bin/sed
+d453932b7d83fc3e183afeca65c1afb2a620b985c378ee072710e0cc593d9811  /after/bin/sed
 bc9ddf9854bd954c71bb1cf5b0af77fd65b8fa7f290b42c75020fb8893deb53c  /after/bin/sha256sum
 957229511dc5ac62a949dbd76e965e3a476ce214b8e6fc7f120bf17d195b924b  /after/bin/tar
 690c2a941c444ba761076f6b8ef1ba2b634ebe2e63ea44c8f3789f6e3df6d2a9  /after/bin/tcc
diff --git a/sysa/run.sh b/sysa/run.sh
index 386942d..024a087 100755
--- a/sysa/run.sh
+++ b/sysa/run.sh
@@ -37,7 +37,7 @@ build musl-1.1.24 musl-1.1.24.sh checksums/pass2
 build tcc-0.9.27 tcc-musl-pass2.sh checksums/tcc-musl-pass2
 
 # Rebuild sed using musl
-build sed-4.0.9
+build sed-4.0.9 sed-4.0.9.sh checksums/pass2
 
 # Rebuild bzip2 using musl
 build bzip2-1.0.8 bzip2-1.0.8.sh checksums/bzip2-pass2
diff --git a/sysa/sed-4.0.7/checksums b/sysa/sed-4.0.7/checksums
deleted file mode 100644
index fd9ef67..0000000
--- a/sysa/sed-4.0.7/checksums
+++ /dev/null
@@ -1 +0,0 @@
-15435 /after/bin/sed
diff --git a/sysa/sed-4.0.9/checksums/pass1 b/sysa/sed-4.0.9/checksums/pass1
new file mode 100644
index 0000000..b014f1a
--- /dev/null
+++ b/sysa/sed-4.0.9/checksums/pass1
@@ -0,0 +1 @@
+10514 /after/bin/sed
diff --git a/sysa/sed-4.0.9/checksums b/sysa/sed-4.0.9/checksums/pass2
similarity index 100%
rename from sysa/sed-4.0.9/checksums
rename to sysa/sed-4.0.9/checksums/pass2
diff --git a/sysa/sed-4.0.7/sed-4.0.7.kaem b/sysa/sed-4.0.9/sed-4.0.9.kaem
similarity index 83%
rename from sysa/sed-4.0.7/sed-4.0.7.kaem
rename to sysa/sed-4.0.9/sed-4.0.9.kaem
index 2487bb4..c3489d5 100755
--- a/sysa/sed-4.0.7/sed-4.0.7.kaem
+++ b/sysa/sed-4.0.9/sed-4.0.9.kaem
@@ -27,7 +27,7 @@ tcc -c getopt1.c
 tcc -c -I .. getopt.c
 tcc -c -I .. -DENABLE_NLS=0 utils.c
 cp regex_.h regex.h
-tcc -c -I . regex.c
+tcc -c -DHAVE_ALLOCA_H -I . regex.c
 tcc -c obstack.c
 tcc -c strverscmp.c
 tcc -c getline.c
@@ -39,12 +39,12 @@ cd ..
 ## sed
 tcc -c -I . -I lib -DSED_FEATURE_VERSION=\"4.0\" sed/compile.c
 tcc -c -I . -I lib sed/execute.c
-tcc -c -I . -I lib sed/regex.c
+tcc -c -I . -I lib sed/regexp.c
 tcc -c -I . -I lib sed/fmt.c
-tcc -c -I . -I lib -DPACKAGE=\"sed\" -DVERSION=\"4.0.7\" sed/sed.c
+tcc -c -I . -I lib -DPACKAGE=\"sed\" -DVERSION=\"4.0.9\" sed/sed.c
 
 # Link
-tcc -static -o ${bindir}/sed -L lib lib/libsed.a compile.o execute.o regex.o fmt.o sed.o -lsed
+tcc -static -o ${bindir}/sed -L lib lib/libsed.a compile.o execute.o regexp.o fmt.o sed.o -lsed
 
 # Test
 sed --version
@@ -52,4 +52,4 @@ sed --version
 cd ../..
 
 # Checksums
-fletcher16 checksums
+fletcher16 checksums/pass1