diff --git a/tracetools_analysis/analysis/callback_duration.ipynb b/tracetools_analysis/analysis/callback_duration.ipynb
index 432f5c4..3e6f044 100644
--- a/tracetools_analysis/analysis/callback_duration.ipynb
+++ b/tracetools_analysis/analysis/callback_duration.ipynb
@@ -100,6 +100,10 @@
     "    if owner_info is None:\n",
     "        owner_info = '[unknown]'\n",
     "\n",
+    "    # Filter out internal subscriptions\n",
+    "    if '/parameter_events' in owner_info:\n",
+    "        continue\n",
+    "\n",
     "    # Duration\n",
     "    duration_df = data_util.get_callback_durations(obj)\n",
     "    starttime = duration_df.loc[:, 'timestamp'].iloc[0].strftime('%Y-%m-%d %H:%M')\n",
@@ -173,6 +177,11 @@
     "\n",
     "colour_i = 0\n",
     "for obj, symbol in callback_symbols.items():\n",
+    "    # Filter out internal subscriptions\n",
+    "    owner_info = data_util.get_callback_owner_info(obj)\n",
+    "    if not owner_info or '/parameter_events' in owner_info:\n",
+    "        continue\n",
+    "\n",
     "    duration_df = data_util.get_callback_durations(obj)\n",
     "    source = ColumnDataSource(duration_df)\n",
     "    duration.title.align = 'center'\n",
@@ -215,7 +224,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.6.9"
+   "version": "3.8.5"
   }
  },
  "nbformat": 4,
diff --git a/tracetools_analysis/analysis/sample_data/converted_pingpong b/tracetools_analysis/analysis/sample_data/converted_pingpong
index ab8f88c..2dabe6e 100644
Binary files a/tracetools_analysis/analysis/sample_data/converted_pingpong and b/tracetools_analysis/analysis/sample_data/converted_pingpong differ