diff --git a/graphify/extract.py b/graphify/extract.py
index b463ae388..2ff478adb 100644
--- a/graphify/extract.py
+++ b/graphify/extract.py
@@ -2527,10 +2527,12 @@ def _astro_mask_non_script(src: str) -> str:
     chars = [c if c in "\r\n" else " " for c in src]
     for start, end in keep:
         chars[start:end] = src[start:end]
-        # Terminate the region in place of the following `<`, so two scripts on
-        # one line don't run together into a single statement.
+        # End a trailing // comment before terminating the statement, as in
+        # the Svelte masker. U+2028 keeps source line numbers unchanged; its
+        # three UTF-8 bytes replace three ASCII bytes from the closing tag.
+        # Frontmatter ends at a preserved newline and needs no terminator.
         if end < len(chars) and chars[end] == " ":
-            chars[end] = ";"
+            chars[end:end + 4] = ["\u2028", ";", "", ""]
     return "".join(chars)
 
 
diff --git a/tests/test_astro_extraction.py b/tests/test_astro_extraction.py
index 2b4fbb344..1772f0545 100644
--- a/tests/test_astro_extraction.py
+++ b/tests/test_astro_extraction.py
@@ -197,3 +197,32 @@ def test_extract_astro_scripts_on_one_line_do_not_merge(tmp_path):
     result = extract_astro(page)
     assert result.get("parse_errors") is None
     assert "b()" in _labels(result)
+
+
+def test_extract_astro_trailing_comment_does_not_hide_next_script(tmp_path):
+    """A comment at the closing tag must end before the next script (#4072)."""
+    page = _write(
+        tmp_path / "inline-comment.astro",
+        "<script>const a = 1 // trailing comment</script>"
+        "<script>function visible() {}</script>\n",
+    )
+    result = extract_astro(page)
+    assert result.get("parse_errors") is None
+    assert _labels(result)["visible()"] == "L1"
+
+
+def test_astro_mask_preserves_bytes_and_newlines_after_comment():
+    from graphify.extract import _astro_mask_non_script
+
+    source = (
+        "---\nconst title = 'hello';\n---\n"
+        "<script>const a = 1 // comment</script>"
+        "<script>function visible() {}</script>\r\n"
+    )
+    masked = _astro_mask_non_script(source).encode("utf-8")
+    original = source.encode("utf-8")
+    assert len(masked) == len(original)
+    assert masked.index(b"function visible") == original.index(b"function visible")
+    assert [(i, c) for i, c in enumerate(masked) if c in (10, 13)] == [
+        (i, c) for i, c in enumerate(original) if c in (10, 13)
+    ]