diff --git a/src/udev/udev-rules.c b/src/udev/udev-rules.c
index 42f6fde8a0..88f633138e 100644
--- a/src/udev/udev-rules.c
+++ b/src/udev/udev-rules.c
@@ -2482,14 +2482,14 @@ static int udev_rule_apply_token_to_event(
 
                         /* Drop the last line. */
                         bool found = false;
-                        for (char *p = PTR_SUB1(buf + strlen(buf), buf); p; p = PTR_SUB1(p, buf))
+                        for (char *p = PTR_SUB1(result + strlen(result), result); p; p = PTR_SUB1(p, result))
                                 if (strchr(NEWLINE, *p)) {
                                         *p = '\0';
                                         found = true;
                                         break;
                                 }
                         if (!found)
-                                buf[0] = '\0';
+                                result[0] = '\0';
                 }
 
                 r = strv_split_newlines_full(&lines, result, EXTRACT_RETAIN_ESCAPE);
diff --git a/test/units/TEST-17-UDEV.IMPORT.sh b/test/units/TEST-17-UDEV.IMPORT.sh
index f09b171066..f2f9a4100e 100755
--- a/test/units/TEST-17-UDEV.IMPORT.sh
+++ b/test/units/TEST-17-UDEV.IMPORT.sh
@@ -17,6 +17,17 @@ test -f /run/udev/data/c1:3
 udevadm info /dev/null | grep 'E: HOGE=aa\\x20\\x20\\x20bb' >/dev/null
 udevadm info /dev/null | grep 'E: FOO=\\x20aaa\\x20' >/dev/null
 
+cat >/run/udev/rules.d/50-testsuite.rules <<'EOF'
+SUBSYSTEM=="mem", KERNEL=="null", OPTIONS="log_level=debug"
+ACTION=="add", SUBSYSTEM=="mem", KERNEL=="null", IMPORT{program}="/bin/sh -c 'printf \"TRUNCATED_OK=yes\nTRUNCATED_BAD=\"; i=0; while [ \"$i\" -lt 20000 ]; do printf A; i=$((i + 1)); done'"
+EOF
+
+udevadm control --reload
+SYSTEMD_LOG_LEVEL=debug udevadm trigger --verbose --settle --action add /dev/null
+
+udevadm info /dev/null | grep 'E: TRUNCATED_OK=yes' >/dev/null
+(! udevadm info /dev/null | grep 'E: TRUNCATED_BAD=' >/dev/null)
+
 rm /run/udev/rules.d/50-testsuite.rules
 udevadm control --reload