diff --git a/apps/kg/eval.py b/apps/kg/eval.py
index 73e89e9153dc..646c1afaa3cd 100644
--- a/apps/kg/eval.py
+++ b/apps/kg/eval.py
@@ -8,7 +8,7 @@
 import time
 import pickle
 
-backend = os.environ.get('DGLBACKEND')
+backend = os.environ.get('DGLBACKEND', 'pytorch')
 if backend.lower() == 'mxnet':
     from train_mxnet import load_model_from_checkpoint
     from train_mxnet import test
diff --git a/apps/kg/models/general_models.py b/apps/kg/models/general_models.py
index a66aad82151d..b9c95d36a3d4 100644
--- a/apps/kg/models/general_models.py
+++ b/apps/kg/models/general_models.py
@@ -2,7 +2,7 @@
 import numpy as np
 import dgl.backend as F
 
-backend = os.environ.get('DGLBACKEND')
+backend = os.environ.get('DGLBACKEND', 'pytorch')
 if backend.lower() == 'mxnet':
     from .mxnet.tensor_models import logsigmoid
     from .mxnet.tensor_models import get_device
diff --git a/apps/kg/tests/test_score.py b/apps/kg/tests/test_score.py
index cfb4eb80367a..1a1f3589707c 100644
--- a/apps/kg/tests/test_score.py
+++ b/apps/kg/tests/test_score.py
@@ -5,7 +5,7 @@
 import dgl.backend as F
 import dgl
 
-backend = os.environ.get('DGLBACKEND')
+backend = os.environ.get('DGLBACKEND', 'pytorch')
 if backend.lower() == 'mxnet':
     import mxnet as mx
     mx.random.seed(42)
diff --git a/apps/kg/train.py b/apps/kg/train.py
index a4edb26831dc..cc3decea9904 100644
--- a/apps/kg/train.py
+++ b/apps/kg/train.py
@@ -6,7 +6,7 @@
 import logging
 import time
 
-backend = os.environ.get('DGLBACKEND')
+backend = os.environ.get('DGLBACKEND', 'pytorch')
 if backend.lower() == 'mxnet':
     import multiprocessing as mp
     from train_mxnet import load_model