diff --git a/gitlint/git.py b/gitlint/git.py
index 9d796f6..e55aa06 100644
--- a/gitlint/git.py
+++ b/gitlint/git.py
@@ -126,7 +126,7 @@
 
     # Split as bytes, as the output may have some non unicode characters.
     blame_lines = subprocess.check_output(
-        ['git', 'blame', commit, '--porcelain', '--', filename]).split(
+        ['git', 'blame', (commit + '^!'), '--porcelain', '--', filename]).split(
             os.linesep.encode('utf-8'))
     modified_line_numbers = utils.filter_lines(
         blame_lines,