diff --git a/invisible_cities/detsim/buffer_functions_test.py b/invisible_cities/detsim/buffer_functions_test.py
index 6e783f772b..c6643ab420 100644
--- a/invisible_cities/detsim/buffer_functions_test.py
+++ b/invisible_cities/detsim/buffer_functions_test.py
@@ -62,6 +62,22 @@ def test_find_signal_start(binned_waveforms, signal_thresh):
     assert np.all(pmt_sum[pulses] > signal_thresh)
 
 
+@mark.parametrize("signal_thresh", (2, 10))
+def test_find_signal_start_numpy(binned_waveforms, signal_thresh):
+
+    pmt_bins, pmt_wfs, *_ = binned_waveforms
+
+    buffer_length = 800 * units.mus
+    bin_width     = np.diff(pmt_bins)[0]
+    stand_off     = int(buffer_length / bin_width)
+
+    pmt_sum       = pmt_wfs.sum()
+    pmt_wfs_np    = np.asarray(pmt_wfs.tolist())
+    pulses        = find_signal_start(pmt_wfs_np, signal_thresh, stand_off)
+
+    assert np.all(pmt_sum[pulses] > signal_thresh)
+
+
 def test_find_signal_start_correct_index():
 
     thresh     = 5
@@ -109,3 +125,38 @@ def test_buffer_calculator(mc_waveforms, binned_waveforms,
         assert evt_pmt .shape[1] == int(buffer_length /  pmt_binwid)
         assert evt_sipm.shape[1] == int(buffer_length / sipm_binwid)
         assert np.sum(evt_pmt, axis=0)[pre_trg_samp] == pmt_sum[pulses[i]]
+
+
+def test_buffer_calculator_pandas_numpy(mc_waveforms, binned_waveforms):
+
+    _, pmt_binwid, sipm_binwid, _ = mc_waveforms
+
+    pmt_bins, pmt_wfs, sipm_bins, sipm_wfs = binned_waveforms
+
+    buffer_length     = 800 * units.mus
+    bin_width         = np.diff(pmt_bins)[0]
+    stand_off         = int(buffer_length / bin_width)
+    pre_trigger       = 100 * units.mus
+    signal_thresh     = 2
+
+    pulses_pd         = find_signal_start(pmt_wfs, signal_thresh, stand_off)
+    pmt_nparr         = np.asarray(pmt_wfs.tolist())
+    pulses_np         = find_signal_start(pmt_nparr, signal_thresh, stand_off)
+
+    calculate_buffers = buffer_calculator(buffer_length,
+                                          pre_trigger  ,
+                                          pmt_binwid   ,
+                                          sipm_binwid  )
+
+    buffers_pd        = calculate_buffers(pulses_pd, *binned_waveforms)
+    buffers_np        = calculate_buffers(pulses_np                    ,
+                                          pmt_bins                     ,
+                                          pmt_nparr                    ,
+                                          sipm_bins                    ,
+                                          np.asarray(sipm_wfs.tolist()))
+
+    assert len(buffers_pd) == len(buffers_np) == 1
+    evtpd_buffers = buffers_pd[0]
+    evtnp_buffers = buffers_np[0]
+    assert np.all([np.all(evtpd_buffers[0] == evtnp_buffers[0]),
+                   np.all(evtpd_buffers[1] == evtnp_buffers[1])])