diff --git a/notebooks/Tracer.ipynb b/notebooks/Tracer.ipynb
index 7b866499..2abee495 100644
--- a/notebooks/Tracer.ipynb
+++ b/notebooks/Tracer.ipynb
@@ -1449,8 +1449,8 @@
     "        # Set new source line\n",
     "        relative_line = given_line - starting_line_number + 1\n",
     "        inject_line = source_lines[relative_line - 1]\n",
-    "        indent = len(inject_line) - len(inject_line.lstrip())\n",
-    "        source_lines[relative_line - 1] = ' ' * indent + TRACER_CODE + inject_line.lstrip()\n",
+    "        indent = inject_line[:len(inject_line) - len(inject_line.lstrip())]\n",
+    "        source_lines[relative_line - 1] = indent + TRACER_CODE + inject_line.lstrip()\n",
     "\n",
     "    # Rename function\n",
     "    new_function_name = function.__name__ + \"_traced\"\n",