diff --git a/src/ice-water-discrimination.jl b/src/ice-water-discrimination.jl
index eda4c4a0..1253a4d7 100644
--- a/src/ice-water-discrimination.jl
+++ b/src/ice-water-discrimination.jl
@@ -75,8 +75,10 @@ function discriminate_ice_water(
     floes_band_1 = @view(image_floes_view[3, :, :])
 
     # keep pixels greater than intensity 100 in bands 2 and 1
-    floes_band_2_keep = floes_band_2[floes_band_2 .> floes_threshold]
-    floes_band_1_keep = floes_band_1[floes_band_1 .> floes_threshold]
+    floes_band_2_keep = floes_band_2[floes_band_2.>floes_threshold]
+    floes_band_1_keep = floes_band_1[floes_band_1.>floes_threshold]
+
+    length(floes_band_2_keep) > 0 || throw(DomainError(floes_band_2_keep, "No elements in floes_band_2 above floes_threshold"))
 
     _, floes_bin_counts = ImageContrastAdjustment.build_histogram(floes_band_2_keep, nbins)
     _, vals = Peaks.findmaxima(floes_bin_counts)