fix SGD lr check (#6244)

1 files changed, 3 insertions, 3 deletions

diff --git a/torch/optim/sgd.py b/torch/optim/sgd.py
index f6d5a484ef..78cb3e189a 100644
--- a/torch/optim/sgd.py
+++ b/torch/optim/sgd.py
@@ -50,11 +50,11 @@ class SGD(Optimizer):
 
     def __init__(self, params, lr=required, momentum=0, dampening=0,
                  weight_decay=0, nesterov=False):
-        if not 0.0 <= lr:
+        if lr is not required and lr < 0.0:
             raise ValueError("Invalid learning rate: {}".format(lr))
-        if not 0.0 <= momentum:
+        if momentum < 0.0:
             raise ValueError("Invalid momentum value: {}".format(momentum))
-        if not 0.0 <= weight_decay:
+        if weight_decay < 0.0:
             raise ValueError("Invalid weight_decay value: {}".format(weight_decay))
 
         defaults = dict(lr=lr, momentum=momentum, dampening=dampening,