diff --git a/src/pytest_markdown_docs/plugin.py b/src/pytest_markdown_docs/plugin.py
index cad6b4e..027396c 100644
--- a/src/pytest_markdown_docs/plugin.py
+++ b/src/pytest_markdown_docs/plugin.py
@@ -115,7 +115,10 @@ def repr_failure(
                     True  # start capturing frames the first time we enter user code
                 )
                 line = (
-                    rawlines[frame_summary.lineno - 1] if frame_summary.lineno else ""
+                    rawlines[frame_summary.lineno - 1]
+                    if frame_summary.lineno is not None
+                    and 1 <= frame_summary.lineno <= len(rawlines)
+                    else ""
                 )
             else:
                 lineno = frame_summary.lineno or 0