diff --git a/deepface/models/Demography.py b/deepface/models/Demography.py
index d0a00f1..7bba87f 100644
--- a/deepface/models/Demography.py
+++ b/deepface/models/Demography.py
@@ -36,7 +36,8 @@ class Demography(ABC):
         assert img_batch.ndim == 4, "expected 4-dimensional tensor input"
 
         if img_batch.shape[0] == 1: # Single image
-            img_batch = img_batch.squeeze(0) # Remove batch dimension
+            if img_batch.shape[-1] != 3: # Check if grayscale
+                img_batch = img_batch.squeeze(0) # Remove batch dimension
             predict_result = self.model(img_batch, training=False).numpy()[0, :] # Predict with legacy method.
             return predict_result
         else: # Batch of images