diff --git a/.github/workflows/go.yml b/.github/workflows/go.yml
index bb4edb4..4bd20fb 100644
--- a/.github/workflows/go.yml
+++ b/.github/workflows/go.yml
@@ -12,10 +12,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
 
-      - name: Set up Go 1.x
+      - name: Set up Go 1.21
         uses: actions/setup-go@v2
         with:
-          go-version: ^1.19
+          go-version: 1.21
         id: go
 
       - name: Check out code into the Go module directory
diff --git a/README.md b/README.md
index 20e937d..8cda7a9 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # Namespaced Merkle Tree (NMT)
 
-![Go version](https://img.shields.io/badge/go-1.19-blue.svg)
+![Go version](https://img.shields.io/badge/go-1.21-blue.svg)
 [![API Reference](https://camo.githubusercontent.com/915b7be44ada53c290eb157634330494ebe3e30a/68747470733a2f2f676f646f632e6f72672f6769746875622e636f6d2f676f6c616e672f6764646f3f7374617475732e737667)](https://pkg.go.dev/github.com/celestiaorg/nmt)
 ![golangci-lint](https://github.com/celestiaorg/nmt/workflows/golangci-lint/badge.svg?branch=master)
 ![Go](https://github.com/celestiaorg/nmt/workflows/Go/badge.svg)
diff --git a/go.mod b/go.mod
index b3b469b..6f42d7e 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module github.com/celestiaorg/nmt
 
-go 1.19
+go 1.21
 
 require (
 	github.com/gogo/protobuf v1.3.2
diff --git a/nmt_test.go b/nmt_test.go
index c4907b5..61da458 100644
--- a/nmt_test.go
+++ b/nmt_test.go
@@ -3,12 +3,12 @@ package nmt
 import (
 	"bytes"
 	"crypto"
+	"crypto/rand"
 	"crypto/sha256"
 	"encoding/binary"
 	"errors"
 	"fmt"
 	"math"
-	"math/rand"
 	"reflect"
 	"sort"
 	"sync"
@@ -534,7 +534,8 @@ func TestNodeVisitor(t *testing.T) {
 		nodeHashes = append(nodeHashes, hash)
 	}
 
-	data := generateRandNamespacedRawData(numLeaves, nidSize, leafSize)
+	data, err := generateRandNamespacedRawData(numLeaves, nidSize, leafSize)
+	require.NoError(t, err)
 	n := New(sha256.New(), NamespaceIDSize(nidSize), NodeVisitor(collectNodeHashes))
 	for j := 0; j < numLeaves; j++ {
 		if err := n.Push(data[j]); err != nil {
@@ -706,7 +707,8 @@ func BenchmarkComputeRoot(b *testing.B) {
 	}
 
 	for _, tt := range tests {
-		data := generateRandNamespacedRawData(tt.numLeaves, tt.nidSize, tt.dataSize)
+		data, err := generateRandNamespacedRawData(tt.numLeaves, tt.nidSize, tt.dataSize)
+		require.NoError(b, err)
 		b.ResetTimer()
 		b.Run(tt.name, func(b *testing.B) {
 			for i := 0; i < b.N; i++ {
@@ -786,21 +788,27 @@ func repeat(data []namespaceDataPair, num int) []namespaceDataPair {
 	return res
 }
 
-func generateRandNamespacedRawData(total int, nidSize int, leafSize int) [][]byte {
+func generateRandNamespacedRawData(total int, nidSize int, leafSize int) ([][]byte, error) {
 	data := make([][]byte, total)
 	for i := 0; i < total; i++ {
 		nid := make([]byte, nidSize)
-		rand.Read(nid)
+		_, err := rand.Read(nid)
+		if err != nil {
+			return nil, err
+		}
 		data[i] = nid
 	}
 	sortByteArrays(data)
 	for i := 0; i < total; i++ {
 		d := make([]byte, leafSize)
-		rand.Read(d)
+		_, err := rand.Read(d)
+		if err != nil {
+			return nil, err
+		}
 		data[i] = append(data[i], d...)
 	}
 
-	return data
+	return data, nil
 }
 
 func sortByteArrays(src [][]byte) {