diff --git a/model_zoo/official/cv/yolov3_darknet53/eval.py b/model_zoo/official/cv/yolov3_darknet53/eval.py
index 7e230e68cf..afa4811f0b 100644
--- a/model_zoo/official/cv/yolov3_darknet53/eval.py
+++ b/model_zoo/official/cv/yolov3_darknet53/eval.py
@@ -173,7 +173,7 @@ class DetectionEngine:
                 y = y.reshape(-1)
                 w = w.reshape(-1)
                 h = h.reshape(-1)
-                cls_emb = cls_emb.reshape(-1, 80)
+                cls_emb = cls_emb.reshape(-1, self.num_classes)
                 conf = conf.reshape(-1)
                 cls_argmax = cls_argmax.reshape(-1)
 
diff --git a/model_zoo/official/cv/yolov3_darknet53/src/config.py b/model_zoo/official/cv/yolov3_darknet53/src/config.py
index 16831b048d..8cf6d18d99 100644
--- a/model_zoo/official/cv/yolov3_darknet53/src/config.py
+++ b/model_zoo/official/cv/yolov3_darknet53/src/config.py
@@ -62,7 +62,7 @@ class ConfigYOLOV3DarkNet53:
                      (116, 90),
                      (156, 198),
                      (373, 326)]
-    out_channel = 255
+    out_channel = 3 * (num_classes + 5)
 
     # test_param
     test_img_shape = [416, 416]