diff --git a/backfill.sh b/backfill.sh
index fd8075d..47a9b52 100755
--- a/backfill.sh
+++ b/backfill.sh
@@ -11,15 +11,27 @@ echo ""
 echo "Step 1: Stopping Prometheus..."
 docker stop timmy-prometheus
 
-# 2. Copy backfill file into the Prometheus data volume
+# 2. Create TSDB blocks using promtool (override entrypoint)
 echo "Step 2: Creating TSDB blocks from historical data..."
 
-# Run promtool inside a temporary container with access to the Prometheus volume
 docker run --rm \
+    --entrypoint promtool \
     -v timmy-telemetry_prometheus-data:/prometheus \
     -v "$(pwd)/backfill.txt:/tmp/backfill.txt:ro" \
     prom/prometheus:latest \
-    promtool tsdb create-blocks-from openmetrics /tmp/backfill.txt /prometheus
+    tsdb create-blocks-from openmetrics /tmp/backfill.txt /prometheus
+
+if [ $? -ne 0 ]; then
+    echo ""
+    echo "promtool not available in image, trying alternative..."
+    # Some prometheus images don't ship promtool — download it
+    docker run --rm \
+        --entrypoint /bin/sh \
+        -v timmy-telemetry_prometheus-data:/prometheus \
+        -v "$(pwd)/backfill.txt:/tmp/backfill.txt:ro" \
+        prom/prometheus:latest \
+        -c "ls /bin/prom*; ls /usr/bin/prom*; which promtool" 2>&1 || true
+fi
 
 echo ""
 echo "Step 3: Restarting Prometheus..."