diff --git a/src/bioclip/predict.py b/src/bioclip/predict.py
index 283b777..22520df 100644
--- a/src/bioclip/predict.py
+++ b/src/bioclip/predict.py
@@ -5,6 +5,7 @@
 import open_clip as oc
 import torch.nn.functional as F
 import numpy as np
+import pandas as pd
 import collections
 import heapq
 import PIL.Image
@@ -272,6 +273,8 @@ class CustomLabelsBinningClassifier(CustomLabelsClassifier):
     def __init__(self, cls_to_bin: dict, **kwargs):
         super().__init__(cls_ary=cls_to_bin.keys(), **kwargs)
         self.cls_to_bin = cls_to_bin
+        if any([pd.isna(x) or not x for x in cls_to_bin.values()]):
+            raise ValueError("Empty, null, or nan are not allowed for bin values.")
 
     def group_probs(self, image_path: str, img_probs: torch.Tensor, k: int = None) -> List[dict[str, float]]:
         result = []
diff --git a/tests/test_predict.py b/tests/test_predict.py
index 41e5700..8ed7914 100644
--- a/tests/test_predict.py
+++ b/tests/test_predict.py
@@ -4,6 +4,7 @@
 from bioclip.predict import CustomLabelsBinningClassifier
 import os
 import torch
+import pandas as pd
 
 
 DIRNAME = os.path.dirname(os.path.realpath(__file__))
@@ -111,6 +112,32 @@ def test_predict_with_bins(self):
         names = set([pred['classification'] for pred in prediction_ary])
         self.assertEqual(names, set(['one', 'two', 'three']))
 
+    def test_predict_with_bins_bad_values(self):
+        with self.assertRaises(ValueError) as raised_exceptions:
+            CustomLabelsBinningClassifier(cls_to_bin={
+                'cat': 'one',
+                'mouse': '',
+                'fish': 'two',
+            })
+        self.assertEqual(str(raised_exceptions.exception),
+                         "Empty, null, or nan are not allowed for bin values.")
+        with self.assertRaises(ValueError) as raised_exceptions:
+            CustomLabelsBinningClassifier(cls_to_bin={
+                'cat': 'one',
+                'mouse': None,
+                'fish': 'two',
+            })
+        self.assertEqual(str(raised_exceptions.exception),
+                         "Empty, null, or nan are not allowed for bin values.")
+        with self.assertRaises(ValueError) as raised_exceptions:
+            CustomLabelsBinningClassifier(cls_to_bin={
+                'cat': 'one',
+                'mouse': pd.NA,
+                'fish': 'two',
+            })
+        self.assertEqual(str(raised_exceptions.exception),
+                         "Empty, null, or nan are not allowed for bin values.")
+
 class TestEmbed(unittest.TestCase):
     def test_get_image_features(self):
         classifier = TreeOfLifeClassifier(device='cpu')