diff --git a/src/stitching_scanner.py b/src/stitching_scanner.py
index 7bcf445..1eba849 100644
--- a/src/stitching_scanner.py
+++ b/src/stitching_scanner.py
@@ -696,7 +696,7 @@ class StitchingScanner:
             
             # ========== DEBUG: Draw borders BEFORE placing strip ==========
             # RED border: Where strip WOULD have been placed (original position)
-            orig_x_end = min(original_x_offset + w_strip, w_base)
+            orig_x_end = min(original_x_offset - w_strip, w_base)
             orig_y_end = min(original_y_offset + h_strip, h_base)
             if original_x_offset >= 0 and original_y_offset >= 0:
                 cv2.rectangle(result,