diff --git a/README.md b/README.md
index 5b7f6a0..f31d191 100644
--- a/README.md
+++ b/README.md
@@ -24,13 +24,8 @@
 
 ## Installation
 
-<<<<<<< HEAD
 - Default CUDA version is `11.8` if CUDA is available otherwise using CPU version.
-- Default Pytorch C++ API version is `1.11.0`
-=======
-- Default CUDA version is `11.7` if CUDA is available otherwise using CPU version.
 - Default Pytorch C++ API version is `2.0.1`
->>>>>>> 83394ef0933537921d2765ccb5e9043671e2edb8
 
 **NOTE**: `libtorch` will be installed at **`/usr/local/lib`**
 
@@ -74,12 +69,8 @@
 ```bash
     wget https://github.com/sugarme/gotch/releases/download/v0.8.0/setup-libtorch.sh
     chmod +x setup-libtorch.sh
-<<<<<<< HEAD
 
     export CUDA_VER=11.8 && bash setup-libtorch.sh
-=======
-    export CUDA_VER=11.7 && bash setup-libtorch.sh
->>>>>>> 83394ef0933537921d2765ccb5e9043671e2edb8
 ```
 
 **Update Environment**: in Debian/Ubuntu, add/update the following lines to `.bashrc` file
@@ -96,12 +87,7 @@
 ```bash
     wget https://github.com/sugarme/gotch/releases/download/v0.8.0/setup-gotch.sh
     chmod +x setup-gotch.sh
-<<<<<<< HEAD
     export CUDA_VER=11.8 && export GOTCH_VER=v0.8.0 && bash setup-gotch.sh
-=======
-    # CUDA 11.7
-    export CUDA_VER=11.7 && export GOTCH_VER=v0.8.0 && bash setup-gotch.sh
->>>>>>> 83394ef0933537921d2765ccb5e9043671e2edb8
 ```
 
 ## Examples
diff --git a/go.mod b/go.mod
index 5ec0e19..6248e03 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module github.com/sugarme/gotch
 
-go 1.19
+go 1.20
 
 require (
 	github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0
diff --git a/nn/optimizer_test.go b/nn/optimizer_test.go
index 9072b4d..8df7af6 100644
--- a/nn/optimizer_test.go
+++ b/nn/optimizer_test.go
@@ -44,6 +44,7 @@ func TestOptimizer(t *testing.T) {
 			fmt.Printf("Loss: %.3f\n", loss.MustView([]int64{-1}, false).MustFloat64Value([]int64{0}))
 		}
 		opt.BackwardStep(loss)
+		loss.MustDrop()
 	}
 
 	loss := x.Apply(model).MustMseLoss(y, 1, true)
diff --git a/setup-gotch.sh b/setup-gotch.sh
index c1dce86..1fea856 100644
--- a/setup-gotch.sh
+++ b/setup-gotch.sh
@@ -1,7 +1,7 @@
 #!/bin/bash
 
-GOTCH_VERSION="${GOTCH_VER:-v0.7.0}"
-CUDA_VERSION="${CUDA_VER:-11.3}"
+GOTCH_VERSION="${GOTCH_VER:-v0.8.0}"
+CUDA_VERSION="${CUDA_VER:-11.8}"
 
 if [ -z $GOPATH ]; then
   GOPATH="$HOME/go"
diff --git a/setup-libtorch.sh b/setup-libtorch.sh
index 87982bb..11693c9 100644
--- a/setup-libtorch.sh
+++ b/setup-libtorch.sh
@@ -1,7 +1,7 @@
 #!/bin/bash
 
 LIBTORCH_VERSION="${LIBTORCH_VER:-2.0.1}"
-CUDA_VERSION="${CUDA_VER:-11.7}"
+CUDA_VERSION="${CUDA_VER:-11.8}"
 
 if [ "${CUDA_VERSION}" == "cpu" ]; then
   CU_VERSION="cpu"