diff --git a/tests/regression/lp-1802581/mock-gpio.py b/tests/lib/fakegpio/fake-gpio.py
similarity index 89%
rename from tests/regression/lp-1802581/mock-gpio.py
rename to tests/lib/fakegpio/fake-gpio.py
index 89ab4448dfd..13e52819009 100755
--- a/tests/regression/lp-1802581/mock-gpio.py
+++ b/tests/lib/fakegpio/fake-gpio.py
@@ -6,6 +6,7 @@
 import os
 import selectors
 import shutil
+import socket
 import subprocess
 import sys
 import tempfile
@@ -59,6 +60,15 @@ def dispatch(sel):
     return True
 
 
+def maybe_sd_notify(s: str) -> None:
+    addr = os.getenv('NOTIFY_SOCKET')
+    if not addr:
+        return
+    soc = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
+    soc.connect(addr)
+    soc.sendall(s.encode())
+
+
 def main():
     """the main method"""
     if os.getuid() != 0:
@@ -83,6 +93,8 @@ def main():
     ufd = os.open("unexport", os.O_RDWR | os.O_NONBLOCK)
     sel.register(efd, selectors.EVENT_READ, export_ready)
     sel.register(ufd, selectors.EVENT_READ, unexport_ready)
+    # notify
+    maybe_sd_notify("READY=1")
     while True:
         if not dispatch(sel):
             break
diff --git a/tests/lib/systemd.sh b/tests/lib/systemd.sh
index 6cef8e82226..52a9d3e7606 100644
--- a/tests/lib/systemd.sh
+++ b/tests/lib/systemd.sh
@@ -10,6 +10,31 @@ systemd_create_and_start_unit() {
     systemctl start "$1"
 }
 
+# Create and start a persistent systemd unit that survives reboots. Use as:
+#   systemd_create_and_start_persistent_unit "name" "my-service --args"
+# The third arg supports "overrides" which allow to customize the service
+# as needed, e.g.:
+#   systemd_create_and_start_persistent_unit "name" "start" "[Unit]\nAfter=foo"
+systemd_create_and_start_persistent_unit() {
+    printf '[Unit]\nDescription=For testing purposes\n[Service]\nType=simple\nExecStart=%s\n[Install]\nWantedBy=multi-user.target\n' "$2" > "/etc/systemd/system/$1.service"
+    if [ -n "${3:-}" ]; then
+        mkdir -p "/etc/systemd/system/$1.service.d"
+        # shellcheck disable=SC2059
+        printf "$3" >> "/etc/systemd/system/$1.service.d/override.conf"
+    fi
+    systemctl daemon-reload
+    systemctl enable "$1"
+    systemctl start "$1"
+    wait_for_service "$1"
+}
+
+system_stop_and_remove_persistent_unit() {
+    systemctl stop "$1" || true
+    systemctl disable "$1" || true
+    rm -f "/etc/systemd/system/$1.service"
+    rm -rf "/etc/systemd/system/$1.service.d"
+}
+
 # Use like systemd_stop_and_destroy_unit(fakestore)
 systemd_stop_and_destroy_unit() {
     if systemctl is-active "$1"; then
diff --git a/tests/main/enable-disable-units-gpio/task.yaml b/tests/main/enable-disable-units-gpio/task.yaml
index e19bd873c22..e308a6493e8 100644
--- a/tests/main/enable-disable-units-gpio/task.yaml
+++ b/tests/main/enable-disable-units-gpio/task.yaml
@@ -12,80 +12,41 @@ details: |
 
 systems: [ubuntu-core-16-64]
 
-environment:
-    GPIO_MOCK_DIR: /home/test/gpio-mock
-
 prepare: |
-    if [ "$TRUST_TEST_KEYS" = "false" ]; then
-        echo "This test needs test keys to be trusted"
-        exit
-    fi
+    # shellcheck source=tests/lib/systemd.sh
+    . "$TESTSLIB/systemd.sh"
+    echo "Create/enable fake gpio"
+    systemd_create_and_start_persistent_unit fake-gpio "$TESTSLIB/fakegpio/fake-gpio.py" "[Unit]\\nBefore=snap.core.interface.gpio-100.service\\n[Service]\\nType=notify"
+
     echo "Given a snap declaring a plug on gpio is installed"
     #shellcheck source=tests/lib/snaps.sh
     . "$TESTSLIB"/snaps.sh
     install_local gpio-consumer
 
-    echo "And a mocked gpio device is in place"
-    cat > /home/test/gpio-mock.sh <<-EOF
-    #!/bin/sh
-    if [ ! -d "$GPIO_MOCK_DIR" ]; then
-        # the service has just been created
-        mkdir -p "$GPIO_MOCK_DIR"
-        touch "$GPIO_MOCK_DIR/gpio100" "$GPIO_MOCK_DIR/export" "$GPIO_MOCK_DIR/unexport"
-    else
-        # after reboot, remove device node to test export
-        rm "$GPIO_MOCK_DIR/gpio100"
-        truncate -s 0 "$GPIO_MOCK_DIR/export"
-    fi
-    mount --bind "$GPIO_MOCK_DIR" /sys/class/gpio
-    EOF
-    chmod a+x /home/test/gpio-mock.sh
-
-    cat > /etc/systemd/system/gpio-mock.service <<-EOF
-    [Unit]
-    Description=Set up mock for gpio test
-    Before=snap.core.interface.gpio-100.service
-
-    [Service]
-    Type=oneshot
-    RemainAfterExit=true
-    ExecStart=/home/test/gpio-mock.sh
-    ExecStop=
-
-    [Install]
-    WantedBy=multi-user.target
-    EOF
-    systemctl enable --now gpio-mock.service
-
     echo "And the gpio plug is connected"
     snap connect gpio-consumer:gpio :gpio-pin
 
 restore: |
-    if [ "$TRUST_TEST_KEYS" = "false" ]; then
-        echo "This test needs test keys to be trusted"
-        exit
-    fi
+    # shellcheck source=tests/lib/systemd.sh
+    . "$TESTSLIB/systemd.sh"
+    system_stop_and_remove_persistent_unit fake-gpio
     umount /sys/class/gpio || true
-    systemctl disable gpio-mock.service
-    rm -rf "$GPIO_MOCK_DIR" /etc/systemd/system/gpio-mock.service /home/test/gpio-mock.sh
 
 execute: |
     # shellcheck source=tests/lib/journalctl.sh
     . "$TESTSLIB/journalctl.sh"
 
-    if [ "$TRUST_TEST_KEYS" = "false" ]; then
-        echo "This test needs test keys to be trusted"
-        exit
-    fi
-
     echo "Then the snap service units concerning the gpio device must be run before and after a reboot"
     expected="Unit snap.core.interface.gpio-100.service has finished starting up"
-    get_journalctl_log -xe --no-pager | MATCH "$expected"
-
-    if [ "$SPREAD_REBOOT" = "1" ]; then
-        MATCH "^100$" < "$GPIO_MOCK_DIR/export"
-    fi
+    for i in $(seq 120); do
+        get_journalctl_log -xe --no-pager | MATCH "$expected"
+        sleep 0.5
+    done
 
     if [ "$SPREAD_REBOOT" = "0" ]; then
         REBOOT
     fi
+
+    if [ "$SPREAD_REBOOT" = "1" ]; then
+        test -e /sys/class/gpio/gpio100
+    fi
diff --git a/tests/regression/lp-1802581/task.yaml b/tests/regression/lp-1802581/task.yaml
index 80a0b8516b0..4d37d906f7b 100644
--- a/tests/regression/lp-1802581/task.yaml
+++ b/tests/regression/lp-1802581/task.yaml
@@ -20,19 +20,20 @@ description: |
 systems: [ubuntu-core-16-64]
 
 prepare: |
-    echo "Run mock gpio daemon"
-    systemd-run --unit mock-gpio -- "$(pwd)/mock-gpio.py"
     # shellcheck source=tests/lib/systemd.sh
     . "$TESTSLIB/systemd.sh"
-    wait_for_service mock-gpio
+    echo "Create/enable fake gpio"
+    systemd_create_and_start_persistent_unit fake-gpio "$TESTSLIB/fakegpio/fake-gpio.py"  "[Unit]\nBefore=snap.core.interface.gpio-100.service\n[Service]\nType=notify"
 
 restore: |
-    systemctl stop mock-gpio || true
-    # for good measure, mock-gpio.py does this umount already on exit
+    # shellcheck source=tests/lib/systemd.sh
+    . "$TESTSLIB/systemd.sh"
+    system_stop_and_remove_persistent_unit fake-gpio
+    # for good measure, fake-gpio.py does this umount already on exit
     umount /sys/class/gpio || true
 
 debug: |
-    journalctl -u mock-gpio.service
+    journalctl -u fake-gpio.service
 
 execute: |
     echo "Install a snap that uses the gpio consumer"
@@ -53,4 +54,4 @@ execute: |
     snap interfaces | MATCH ":gpio-pin.*gpio-consumer:gpio"
 
     echo "Ensure that our mock service is full functional"
-    systemctl status mock-gpio.service | MATCH "Active: active"
+    systemctl status fake-gpio.service | MATCH "Active: active"