diff --git a/notebooks_tsqr/NightLog.ipynb b/notebooks_tsqr/NightLog.ipynb
index 1e5889b..3bdeaa1 100644
--- a/notebooks_tsqr/NightLog.ipynb
+++ b/notebooks_tsqr/NightLog.ipynb
@@ -305,7 +305,8 @@
     "# Exposure Tally\n",
     "md(f\"## Exposure Tally for all Instruments\")\n",
     "tally = await allsrc.night_tally_observation_gaps()\n",
-    "display(pd.DataFrame(tally))\n",
+    "if tally:\n",
+    "    display(pd.DataFrame(tally))\n",
     "\n",
     "# Observation gaps\n",
     "gaps = allsrc.exp_src.get_observation_gaps()\n",
@@ -332,13 +333,23 @@
    "id": "17",
    "metadata": {},
    "outputs": [],
+   "source": [
+    "tally"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "18",
+   "metadata": {},
+   "outputs": [],
    "source": [
     "gaps"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "18",
+   "id": "19",
    "metadata": {},
    "source": [
     "# Narrative Log\n"
@@ -347,7 +358,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "19",
+   "id": "20",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -363,7 +374,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "20",
+   "id": "21",
    "metadata": {},
    "source": [
     "# Developer Only Section"
@@ -371,7 +382,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "21",
+   "id": "22",
    "metadata": {},
    "source": [
     "## Where was this run?\n",
@@ -387,7 +398,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "22",
+   "id": "23",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -400,7 +411,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "23",
+   "id": "24",
    "metadata": {},
    "source": [
     "# Finale"
@@ -409,7 +420,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "24",
+   "id": "25",
    "metadata": {},
    "outputs": [],
    "source": [
diff --git a/python/lsst/ts/logging_and_reporting/all_sources.py b/python/lsst/ts/logging_and_reporting/all_sources.py
index 7f88b16..4761961 100644
--- a/python/lsst/ts/logging_and_reporting/all_sources.py
+++ b/python/lsst/ts/logging_and_reporting/all_sources.py
@@ -80,7 +80,7 @@ async def night_tally_observation_gaps(self, verbose=True):
             )
 
         if targets.empty:
-            return dict
+            return None
 
         num_slews = targets[["slewTime"]].astype(bool).sum(axis=0).squeeze()
         total_slew_seconds = targets[["slewTime"]].sum().squeeze()