diff --git a/preprocess_cancellation.py b/preprocess_cancellation.py
index 270926a..a5e89f2 100644
--- a/preprocess_cancellation.py
+++ b/preprocess_cancellation.py
@@ -5,14 +5,15 @@
 import json
 import logging
 import pathlib
-import platform
 import re
 import shutil
 import statistics
 import sys
 import tempfile
-import time
-from typing import Any, Dict, List, NamedTuple, Optional, Set, Tuple, TypeVar
+from typing import Dict, List, NamedTuple, Optional, Set, Tuple, TypeVar
+
+__version__ = "0.1.7"
+
 
 logging.basicConfig(stream=sys.stderr, level=logging.INFO)
 logger = logging.getLogger("prepropress_cancellation")
@@ -25,8 +26,7 @@
 except OSError:
     logger.exception("Failed to import shapely. Are you missing libgeos?")
 
-
-HEADER_MARKER = "; Pre-Processed for Cancel-Object support\n"
+HEADER_MARKER = f"; Pre-Processed for Cancel-Object support by preprocess_cancellation v{__version__}\n"
 
 
 PathLike = TypeVar("PathLike", str, pathlib.Path)
@@ -332,15 +332,19 @@ def preprocess_slicer(infile):
     infile.seek(0)
     for line in infile:
         yield line
+        if line.strip() and not line.startswith(";"):
+            break
 
-        if line.startswith("; generated by"):
-            yield from header(len(known_objects))
-            for object_id, hull in known_objects.values():
-                yield from define_object(
-                    object_id,
-                    center=hull.center(),
-                    polygon=hull.exterior(),
-                )
+    yield from header(len(known_objects))
+    for object_id, hull in known_objects.values():
+        yield from define_object(
+            object_id,
+            center=hull.center(),
+            polygon=hull.exterior(),
+        )
+
+    for line in infile:
+        yield line
 
         if line.startswith("; printing object "):
             yield from object_start_marker(known_objects[line.split("printing object")[1].strip()].name)
diff --git a/pyproject.toml b/pyproject.toml
index 40fa674..22d44c8 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "preprocess_cancellation"
-version = "0.1.6"
+version = "0.1.7"
 description = "GCode processor to add klipper cancel-object markers"
 readme = "README.md"
 authors = ["Franklyn Tackitt <im@frank.af>"]