diff --git a/tessreduce/helpers.py b/tessreduce/helpers.py
index 3c88e4a..8a0686a 100644
--- a/tessreduce/helpers.py
+++ b/tessreduce/helpers.py
@@ -13,6 +13,7 @@
 from scipy.ndimage import shift
 from scipy.ndimage import gaussian_filter
 from scipy.ndimage import convolve
+from scipy.ndimage import label
 from scipy.signal import savgol_filter
 from scipy.interpolate import interp1d
 from scipy.interpolate import griddata