diff --git a/testdata/moonfire-nvr/movement_detection_via_api_ffmpeg.sh b/testdata/moonfire-nvr/movement_detection_via_api_ffmpeg.sh
index 782ac7a..5c7cb35 100644
--- a/testdata/moonfire-nvr/movement_detection_via_api_ffmpeg.sh
+++ b/testdata/moonfire-nvr/movement_detection_via_api_ffmpeg.sh
@@ -74,17 +74,20 @@ main() {
             echo "$uuid.$recording" >> /tmp/movement_detection_via_api_ffmpeg.sh.txt
             echo "$cksum" >> /tmp/movement_detection_via_api_ffmpeg.sh.txt
          else
-            local next_recording=$(( ${recordings[recording_idx]} - 1 ))
-            local span="$recording"
-            if [ "$recording" != "$next_recording" ]; then
-               span="$recording-$next_recording"
+            local next_recording=${recordings[recording_idx]}
+            if [ -z "$next_recording" ] || [ "$recording" == "$next_recording" ]; then
+               next_recording="$recording"
+            else
+               next_recording=$((next_recording-1))
             fi
-            echo no movement in "$span"
-            for stream in ${streams[@]}; do
-               api "/api/cameras/$uuid/$stream/view.mp4" \
-                  -X DELETE \
-                  -H 'Content-Type: application/json' \
-                  -d "$(printf '{"s": "%s"}' "$span")"
+            echo no movement in "$recording..$next_recording"
+            for j in $(seq $recording $next_recording); do
+               for stream in ${streams[@]}; do
+                  api "/api/cameras/$uuid/$stream/view.mp4" \
+                     -X DELETE \
+                     -H 'Content-Type: application/json' \
+                     -d "$(printf '{"s": "%s"}' "$j")"
+               done
             done
          fi
       done