diff --git a/contrib/guix/README.md b/contrib/guix/README.md
index 9f99b36f88..8ce8cb97a0 100644
--- a/contrib/guix/README.md
+++ b/contrib/guix/README.md
@@ -13,7 +13,6 @@ We achieve bootstrappability by using Guix as a functional package manager.
 
 Conservatively, a x86_64 machine with:
 
-- 2 or more logical cores
 - 4GB of free disk space on the partition that /gnu/store will reside in
 - 24GB of free disk space on the partition that the Bitcoin Core git repository
   resides in
diff --git a/contrib/guix/guix-build.sh b/contrib/guix/guix-build.sh
index e20b2a048d..11d2c8b867 100755
--- a/contrib/guix/guix-build.sh
+++ b/contrib/guix/guix-build.sh
@@ -105,6 +105,7 @@ for host in ${HOSTS=x86_64-linux-gnu arm-linux-gnueabihf aarch64-linux-gnu riscv
                                  --pure \
                                  --no-cwd \
                                  --share="$PWD"=/bitcoin \
+                                 --expose="$(git rev-parse --git-common-dir)" \
                                  ${SOURCES_PATH:+--share="$SOURCES_PATH"} \
                                  ${ADDITIONAL_GUIX_ENVIRONMENT_FLAGS} \
                                  -- env HOST="$host" \
diff --git a/contrib/guix/libexec/build.sh b/contrib/guix/libexec/build.sh
index 94b7b6fd97..62d1f1edc7 100644
--- a/contrib/guix/libexec/build.sh
+++ b/contrib/guix/libexec/build.sh
@@ -141,19 +141,17 @@ make -C depends --jobs="$MAX_JOBS" HOST="$HOST" \
 # Source Tarball Building #
 ###########################
 
-# Create the source tarball and move it to "${OUTDIR}/src" if not already there
-if [ -z "$(find "${OUTDIR}/src" -name 'bitcoin-*.tar.gz')" ]; then
-    ./autogen.sh
-    env CONFIG_SITE="${BASEPREFIX}/${HOST}/share/config.site" ./configure --prefix=/
-    make dist GZIP_ENV='-9n' ${V:+V=1}
-    mkdir -p "${OUTDIR}/src"
-    mv "$(find "${PWD}" -name 'bitcoin-*.tar.gz')" "${OUTDIR}/src/"
-fi
+# Define DISTNAME variable.
+# shellcheck source=contrib/gitian-descriptors/assign_DISTNAME
+source contrib/gitian-descriptors/assign_DISTNAME
 
-# Determine the full path to our source tarball
-SOURCEDIST="$(find "${OUTDIR}/src" -name 'bitcoin-*.tar.gz')"
-# Determine our distribution name (e.g. bitcoin-0.18.0)
-DISTNAME="$(basename "$SOURCEDIST" '.tar.gz')"
+GIT_ARCHIVE="${OUTDIR}/src/${DISTNAME}.tar.gz"
+
+# Create the source tarball if not already there
+if [ ! -e "$GIT_ARCHIVE" ]; then
+    mkdir -p "$(dirname "$GIT_ARCHIVE")"
+    git archive --output="$GIT_ARCHIVE" HEAD
+fi
 
 ###########################
 # Binary Tarball Building #
@@ -187,7 +185,9 @@ export PATH="${BASEPREFIX}/${HOST}/native/bin:${PATH}"
     cd "$DISTSRC"
 
     # Extract the source tarball
-    tar --strip-components=1 -xf "${SOURCEDIST}"
+    tar -xf "${GIT_ARCHIVE}"
+
+    ./autogen.sh
 
     # Configure this DISTSRC for $HOST
     # shellcheck disable=SC2086
@@ -221,7 +221,7 @@ export PATH="${BASEPREFIX}/${HOST}/native/bin:${PATH}"
     # Make the os-specific installers
     case "$HOST" in
         *mingw*)
-            make deploy ${V:+V=1}
+            make deploy ${V:+V=1} BITCOIN_WIN_INSTALLER="${OUTDIR}/${DISTNAME}-win64-setup-unsigned.exe"
             ;;
     esac
 
@@ -233,11 +233,6 @@ export PATH="${BASEPREFIX}/${HOST}/native/bin:${PATH}"
     # Install built Bitcoin Core to $INSTALLPATH
     make install DESTDIR="${INSTALLPATH}" ${V:+V=1}
 
-    case "$HOST" in
-        *mingw*)
-            cp -f --target-directory="$OUTDIR" ./*-setup-unsigned.exe
-            ;;
-    esac
     (
         cd installed
 
@@ -265,7 +260,7 @@ export PATH="${BASEPREFIX}/${HOST}/native/bin:${PATH}"
                 cp "${DISTSRC}/doc/README_windows.txt" "${DISTNAME}/readme.txt"
                 ;;
             *linux*)
-                cp "${DISTSRC}/doc/README.md" "${DISTNAME}/"
+                cp "${DISTSRC}/README.md" "${DISTNAME}/"
                 ;;
         esac
 
@@ -308,7 +303,7 @@ case "$HOST" in
         (
             cd ./windeploy
             mkdir unsigned
-            cp --target-directory=unsigned/ "$OUTDIR"/bitcoin-*-setup-unsigned.exe
+            cp --target-directory=unsigned/ "${OUTDIR}/${DISTNAME}-win64-setup-unsigned.exe"
             find . -print0 \
                 | sort --zero-terminated \
                 | tar --create --no-recursion --mode='u+rw,go+r-w,a+X' --null --files-from=- \
diff --git a/contrib/guix/manifest.scm b/contrib/guix/manifest.scm
index c99b417815..346a0cb0be 100644
--- a/contrib/guix/manifest.scm
+++ b/contrib/guix/manifest.scm
@@ -18,6 +18,7 @@
              (gnu packages python)
              (gnu packages shells)
              (gnu packages bison)
+             (gnu packages version-control)
              (guix build-system gnu)
              (guix build-system trivial)
              (guix gexp)
@@ -183,6 +184,8 @@ chain for " target " development."))
         ;; Scripting
         perl
         python-3.7
+        ;; Git
+        git
         ;; Native gcc 9 toolchain targeting glibc 2.27
         (make-gcc-toolchain gcc-9 glibc-2.27))
   (let ((target (getenv "HOST")))