diff --git a/synterloper/synterloper.sh b/synterloper/synterloper.sh
index fa1c770..767a564 100644
--- a/synterloper/synterloper.sh
+++ b/synterloper/synterloper.sh
@@ -61,7 +61,10 @@ Description=SYNterloper - TCP Port Connection Logger
 After=network.target
 [Service]
 Type=simple
-ExecStart=/bin/sh -c 'exec /usr/sbin/tcpdump -i \$(ip -4 route get 1.1.1.1 | grep -oP "dev \\K\\S+") -s ${SNAP_LEN} -w ${LOG_DIR}/capture-%Y-%m-%d_%H-%M.pcap -G ${ROTATE_SECONDS} "tcp port ${CAPTURE_PORT}"'
+# =========================================================================================
+# THE FIX IS HERE: All '%' are escaped as '%%' for systemd
+# =========================================================================================
+ExecStart=/bin/sh -c 'exec /usr/sbin/tcpdump -i \$(ip -4 route get 1.1.1.1 | grep -oP "dev \\K\\S+") -s ${SNAP_LEN} -w ${LOG_DIR}/capture-%%Y-%%m-%%d_%%H-%%M.pcap -G ${ROTATE_SECONDS} "tcp port ${CAPTURE_PORT}"'
 Restart=on-failure
 RestartSec=5
 [Install]
@@ -72,6 +75,7 @@ EOF
         systemctl enable synterloper.service
         systemctl start synterloper.service
     elif [ "${OS_TYPE}" = "FreeBSD" ]; then
+        # FreeBSD's rc.d system does not have this issue, so no change is needed here.
         echo "Creating rc.d script: /usr/local/etc/rc.d/synterloper"
         cat > /usr/local/etc/rc.d/synterloper <<'EOF'
 #!/bin/sh