diff --git a/test-all-native.sh b/test-all-native.sh
index 05236aa..df150e1 100755
--- a/test-all-native.sh
+++ b/test-all-native.sh
@@ -794,6 +794,22 @@ grep -F 'linuxcnc_unclosed_comment_error|Unclosed comment found' test-linuxcnc-r
 grep -F 'linuxcnc_nested_comment_error|Nested comment found' test-linuxcnc-rs274-native.sh >/dev/null
 grep -F 'linuxcnc_commented_percent_error|Bad character '\''%'\'' used' test-linuxcnc-rs274-native.sh >/dev/null
 grep -F 'linuxcnc_mid_program_percent_error|Bad character '\''%'\'' used' test-linuxcnc-rs274-native.sh >/dev/null
+python3 - <<'PY'
+from pathlib import Path
+
+fixtures = sorted(path.stem for path in Path("tests/gcode").glob("linuxcnc_*.ngc"))
+for label, script in [
+    ("native RS274", Path("test-linuxcnc-rs274-native.sh")),
+    ("source-linked RS274", Path("test-linuxcnc-source-link.sh")),
+]:
+    text = script.read_text(encoding="utf-8")
+    missing = [fixture for fixture in fixtures if fixture not in text]
+    if missing:
+        raise SystemExit(
+            f"{label} regression script no longer covers LinuxCNC fixtures: "
+            + ", ".join(missing)
+        )
+PY
 
 for script in \
     test-native.sh \