diff --git a/projects/sandbox/train/train/augmentor.py b/projects/sandbox/train/train/augmentor.py
index edc39b886..3f60aa9a9 100644
--- a/projects/sandbox/train/train/augmentor.py
+++ b/projects/sandbox/train/train/augmentor.py
@@ -211,28 +211,30 @@ def forward(self, X):
         # sample waveforms and use them to compute
         # interferometer responses
         N = mask.sum().item()
-        responses = self.sample_responses(N, X.shape[-1], psds[mask])
-        responses.to(X.device)
 
-        # perform swapping and muting augmentations
-        # on those responses, and then inject them
-        responses, swap_indices = self.swapper(responses)
-        responses, mute_indices = self.muter(responses)
-        X[mask] += responses
+        if N > 0:
+            responses = self.sample_responses(N, X.shape[-1], psds[mask])
+            responses.to(X.device)
+
+            # perform swapping and muting augmentations
+            # on those responses, and then inject them
+            responses, swap_indices = self.swapper(responses)
+            responses, mute_indices = self.muter(responses)
+            X[mask] += responses
+            
+            # set response augmentation labels to noise
+            idx = torch.where(mask)[0]
+            mask[idx[mute_indices]] = 0
+            mask[idx[swap_indices]] = 0
+
+            # set labels to positive for injected signals
+            y[mask] = -y[mask] + 1
 
         # now that injections have been made,
         # whiten _all_ the strain using the
         # background psds computed up top
         X = self.whitener(X, psds)
 
-        # set response augmentation labels to noise
-        idx = torch.where(mask)[0]
-        mask[idx[mute_indices]] = 0
-        mask[idx[swap_indices]] = 0
-
-        # set labels to positive for injected signals
-        y[mask] = -y[mask] + 1
-
         # curriculum learning step
         if self.snr is not None:
             self.snr.step()
diff --git a/projects/sandbox/train/train/train.py b/projects/sandbox/train/train/train.py
index d43cdf0d8..80f4d1dfa 100644
--- a/projects/sandbox/train/train/train.py
+++ b/projects/sandbox/train/train/train.py
@@ -228,6 +228,12 @@ def main(
     sample_length = window_length + psd_length
     fftlength = fftlength or window_length
 
+    if psd_length < window_length:
+        raise ValueError(
+	     "Can't have psd length shorter than "
+	     "window length, {} < {}".format(psd_length, window_length)
+        )
+
     # create objects that we'll use for whitening the data
     fast = highpass is not None
     psd_estimator = PsdEstimator(