diff --git a/meta/classes/dpkg-base.bbclass b/meta/classes/dpkg-base.bbclass
index 95cc830d..20c59ce8 100644
--- a/meta/classes/dpkg-base.bbclass
+++ b/meta/classes/dpkg-base.bbclass
@@ -80,102 +80,28 @@ do_adjust_git[lockfiles] += "${DL_DIR}/git/isar.lock"
 inherit patch
 addtask patch after do_adjust_git
 
-SRC_APT ?= ""
-
-# filter out all "apt://" URIs out of SRC_URI and stick them into SRC_APT
 python() {
-    src_uri = (d.getVar('SRC_URI', False) or "").split()
+    from bb.fetch2 import methods
 
-    prefix = "apt://"
-    src_apt = []
-    for u in src_uri:
-        if u.startswith(prefix):
-            src_apt.append(u[len(prefix) :])
-            d.setVar('SRC_URI:remove', u)
+    # apt-src fetcher
+    import aptsrc_fetcher
+    methods.append(aptsrc_fetcher.AptSrc())
 
-    d.prependVar('SRC_APT', ' '.join(src_apt))
+    src_uri = (d.getVar('SRC_URI', False) or "").split()
+    for u in src_uri:
+        if u.startswith("apt://"):
+            d.appendVarFlag('do_fetch', 'depends', d.getVar('SCHROOT_DEP'))
 
-    if len(d.getVar('SRC_APT').strip()) > 0:
-        bb.build.addtask('apt_unpack', 'do_patch', '', d)
-        bb.build.addtask('cleanall_apt', 'do_cleanall', '', d)
+            d.appendVarFlag('do_unpack', 'cleandirs', d.getVar('S'))
+            d.setVarFlag('do_unpack', 'network', d.getVar('TASK_USE_SUDO'))
+            break
 
     # container docker fetcher
     import container_fetcher
-    from bb.fetch2 import methods
 
     methods.append(container_fetcher.Container())
 }
 
-do_apt_fetch() {
-    E="${@ isar_export_proxies(d)}"
-    schroot_create_configs
-
-    session_id=$(schroot -q -b -c ${SBUILD_CHROOT})
-    echo "Started session: ${session_id}"
-
-    schroot_cleanup() {
-        schroot -q -f -e -c ${session_id} > /dev/null 2>&1
-        schroot_delete_configs
-    }
-    trap 'exit 1' INT HUP QUIT TERM ALRM USR1
-    trap 'schroot_cleanup' EXIT
-
-    schroot -r -c ${session_id} -d / -u root -- \
-        rm /etc/apt/sources.list.d/isar-apt.list /etc/apt/preferences.d/isar-apt
-    schroot -r -c ${session_id} -d / -- \
-        sh -c '
-            set -e
-            for uri in $2; do
-                mkdir -p /downloads/deb-src/"$1"/${uri}
-                cd /downloads/deb-src/"$1"/${uri}
-                apt-get -y --download-only --only-source source ${uri}
-            done' \
-                my_script "${BASE_DISTRO}-${BASE_DISTRO_CODENAME}" "${SRC_APT}"
-
-    schroot -e -c ${session_id}
-    schroot_delete_configs
-}
-
-addtask apt_fetch
-do_apt_fetch[lockfiles] += "${REPO_ISAR_DIR}/isar.lock"
-do_apt_fetch[network] = "${TASK_USE_NETWORK_AND_SUDO}"
-
-# Add dependency from the correct schroot: host or target
-do_apt_fetch[depends] += "${SCHROOT_DEP}"
-
-do_apt_unpack() {
-    rm -rf ${S}
-    schroot_create_configs
-
-    schroot_cleanup() {
-        schroot_delete_configs
-    }
-    trap 'exit 1' INT HUP QUIT TERM ALRM USR1
-    trap 'schroot_cleanup' EXIT
-
-    schroot -d / -c ${SBUILD_CHROOT} -- \
-        sh -c '
-            set -e
-            for uri in $2; do
-                dscfile="$(apt-get -y -qq --print-uris --only-source source $uri | cut -d " " -f2 | grep -E "*.dsc")"
-                cd ${PP}
-                cp /downloads/deb-src/"${1}"/${uri}/* ${PP}
-                dpkg-source -x "${dscfile}" "${PPS}"
-            done' \
-                my_script "${BASE_DISTRO}-${BASE_DISTRO_CODENAME}" "${SRC_APT}"
-    schroot_delete_configs
-}
-do_apt_unpack[network] = "${TASK_USE_SUDO}"
-
-addtask apt_unpack after do_apt_fetch
-
-do_cleanall_apt[nostamp] = "1"
-do_cleanall_apt() {
-    for uri in "${SRC_APT}"; do
-        rm -rf "${DEBSRCDIR}/${BASE_DISTRO}-${BASE_DISTRO_CODENAME}/$uri"
-    done
-}
-
 def get_package_srcdir(d):
     s = os.path.abspath(d.getVar("S"))
     workdir = os.path.abspath(d.getVar("WORKDIR"))
diff --git a/meta/lib/aptsrc_fetcher.py b/meta/lib/aptsrc_fetcher.py
new file mode 100644
index 00000000..2a4b5b9d
--- /dev/null
+++ b/meta/lib/aptsrc_fetcher.py
@@ -0,0 +1,86 @@
+# This software is a part of ISAR.
+# Copyright (c) Siemens AG, 2024
+#
+# SPDX-License-Identifier: MIT
+
+from bb.fetch2 import FetchError
+from bb.fetch2 import FetchMethod
+from bb.fetch2 import logger
+from bb.fetch2 import runfetchcmd
+
+class AptSrc(FetchMethod):
+    def supports(self, ud, d):
+        return ud.type in ['apt']
+
+    def urldata_init(self, ud, d):
+        ud.src_package = ud.url[len('apt://'):]
+        ud.host = ud.host.replace('=', '_')
+
+        base_distro = d.getVar('BASE_DISTRO')
+
+        # For these distros we know that the same version means the same
+        # source package, also across distro releases.
+        distro_suffix = '' if base_distro in ['debian', 'ubuntu'] else \
+            '-' + d.getVar('BASE_DISTRO_CODENAME')
+
+        ud.localfile='deb-src/' + base_distro + distro_suffix + '/' + ud.host
+
+    def download(self, ud, d):
+        bb.utils.exec_flat_python_func('isar_export_proxies', d)
+        bb.build.exec_func('schroot_create_configs', d)
+
+        sbuild_chroot = d.getVar('SBUILD_CHROOT')
+        session_id = runfetchcmd(f'schroot -q -b -c {sbuild_chroot}', d).strip()
+        logger.info(f'Started session: {session_id}')
+
+        repo_isar_dir = d.getVar('REPO_ISAR_DIR')
+        lockfile = bb.utils.lockfile(f'{repo_isar_dir}/isar.lock')
+
+        try:
+            runfetchcmd(f'''
+                set -e
+                schroot -r -c {session_id} -d / -u root -- \
+                    rm /etc/apt/sources.list.d/isar-apt.list /etc/apt/preferences.d/isar-apt
+                schroot -r -c {session_id} -d / -- \
+                    sh -c '
+                        set -e;
+                        mkdir -p /downloads/{ud.localfile}
+                        cd /downloads/{ud.localfile}
+                        apt-get -y --download-only --only-source source {ud.src_package}
+                        '
+                ''', d)
+        except (OSError, FetchError):
+            raise
+        finally:
+            bb.utils.unlockfile(lockfile)
+            runfetchcmd(f'schroot -q -f -e -c {session_id}', d)
+            bb.build.exec_func('schroot_delete_configs', d)
+
+    def unpack(self, ud, rootdir, d):
+        bb.build.exec_func('schroot_create_configs', d)
+
+        sbuild_chroot = d.getVar('SBUILD_CHROOT')
+        pp = d.getVar('PP')
+        pps = d.getVar('PPS')
+        try:
+            runfetchcmd(f'''
+                schroot -d / -c {sbuild_chroot} -- \
+                    sh -c '
+                        set -e
+                        dscfile=$(apt-get -y -qq --print-uris --only-source source {ud.src_package} | \
+                                  cut -d " " -f2 | grep -E "\.dsc")
+                        cp /downloads/{ud.localfile}/* {pp}
+                        cd {pp}
+                        mv -f {pps} {pps}.prev
+                        dpkg-source -x "$dscfile" {pps}
+                        find {pps}.prev -mindepth 1 -maxdepth 1 -exec mv {{}} {pps}/ \;
+                        rmdir {pps}.prev
+                        '
+                ''', d)
+        except (OSError, FetchError):
+            raise
+        finally:
+            bb.build.exec_func('schroot_delete_configs', d)
+
+    def clean(self, ud, d):
+        bb.utils.remove(ud.localpath, recurse=True)
