diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0c99ac0..7747540 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -51,7 +51,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        goversion: ["1.17", "1.18", "1.19"]
+        goversion: ["1.17", "1.18", "1.19", "1.20"]
 
     name: Build & Test (Linux, Go ${{ matrix.goversion }})
     needs: [lint]
@@ -75,7 +75,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        goversion: ["1.17", "1.18", "1.19"]
+        goversion: ["1.17", "1.18", "1.19", "1.20"]
 
     name: Build & Test (Windows, Go ${{ matrix.goversion }})
     needs: [lint]
@@ -99,7 +99,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        goversion: ["1.17", "1.18", "1.19"]
+        goversion: ["1.17", "1.18", "1.19", "1.20"]
 
     name: Build & Test (macOS, Go ${{ matrix.goversion }})
     needs: [lint]
@@ -128,4 +128,4 @@ jobs:
       - name: Check all tests passed
         uses: re-actors/alls-green@release/v1
         with:
-          jobs: ${{ toJSON(needs) }}
\ No newline at end of file
+          jobs: ${{ toJSON(needs) }}
diff --git a/.github/workflows/pkg.yml b/.github/workflows/pkg.yml
index f282cc2..dd43fce 100644
--- a/.github/workflows/pkg.yml
+++ b/.github/workflows/pkg.yml
@@ -25,7 +25,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v3
         with:
-          go-version: 1.19
+          go-version: "1.20"
 
       - name: Build package
         env:
@@ -56,7 +56,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v3
         with:
-          go-version: 1.19
+          go-version: "1.20"
 
       - name: Build package
         env:
@@ -87,7 +87,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v3
         with:
-          go-version: 1.19
+          go-version: "1.20"
 
       - name: Build package
         run: sh contrib/msi/build-msi.sh ${{ matrix.pkgarch }}
@@ -122,7 +122,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v3
         with:
-          go-version: 1.19
+          go-version: "1.20"
 
       - name: Build package
         env:
diff --git a/src/tun/tun.go b/src/tun/tun.go
index ce1bd16..fcd597b 100644
--- a/src/tun/tun.go
+++ b/src/tun/tun.go
@@ -107,7 +107,8 @@ func (tun *TunAdapter) _start() error {
 	}
 	tun.addr = tun.rwc.Address()
 	tun.subnet = tun.rwc.Subnet()
-	addr := fmt.Sprintf("%s/%d", net.IP(tun.addr[:]).String(), 8*len(address.GetPrefix())-1)
+	prefix := address.GetPrefix()
+	addr := fmt.Sprintf("%s/%d", net.IP(tun.addr[:]).String(), 8*len(prefix[:])-1)
 	if tun.config.name == "none" || tun.config.name == "dummy" {
 		tun.log.Debugln("Not starting TUN as ifname is none or dummy")
 		tun.isEnabled = false