diff --git a/providers/fs/fs.go b/providers/fs/fs.go
index 0df2de04..c008b427 100644
--- a/providers/fs/fs.go
+++ b/providers/fs/fs.go
@@ -9,8 +9,8 @@ package fs
 
 import (
 	"errors"
-	"io"
 	"io/fs"
+	"io/ioutil"
 )
 
 // FS implements an fs.FS provider.
@@ -32,7 +32,7 @@ func (f *FS) ReadBytes() ([]byte, error) {
 	}
 	defer fd.Close()
 
-	return io.ReadAll(fd)
+	return ioutil.ReadAll(fd)
 }
 
 // Read is not supported by the fs.FS provider.
diff --git a/providers/s3/s3.go b/providers/s3/s3.go
index 4c7c7e2f..13e63436 100644
--- a/providers/s3/s3.go
+++ b/providers/s3/s3.go
@@ -4,7 +4,7 @@ package s3
 
 import (
 	"errors"
-	"io"
+	"io/ioutil"
 
 	"github.com/rhnvrm/simples3"
 )
@@ -56,7 +56,7 @@ func (r *S3) ReadBytes() ([]byte, error) {
 
 	defer resp.Close()
 
-	data, err := io.ReadAll(resp)
+	data, err := ioutil.ReadAll(resp)
 	if err != nil {
 		return nil, err
 	}
diff --git a/tests/koanf_test.go b/tests/koanf_test.go
index ddc96fba..bd2bd509 100644
--- a/tests/koanf_test.go
+++ b/tests/koanf_test.go
@@ -5,6 +5,7 @@ import (
 	"errors"
 	"flag"
 	"fmt"
+	"io/ioutil"
 	"log"
 	"os"
 	"path/filepath"
@@ -437,9 +438,9 @@ func TestWatchFile(t *testing.T) {
 	)
 
 	// Create a tmp config file.
-	tmpDir := t.TempDir()
+	tmpDir, _ := ioutil.TempDir("", "koanf_*") // TODO: replace with t.TempDir() as of go v1.15
 	tmpFile := filepath.Join(tmpDir, "koanf_mock")
-	err := os.WriteFile(tmpFile, []byte(`{"parent": {"name": "name1"}}`), 0600)
+	err := ioutil.WriteFile(tmpFile, []byte(`{"parent": {"name": "name1"}}`), 0600) // TODO: replace with os.WriteFile as of go v1.16
 	require.NoError(t, err, "error creating temp config file: %v", err)
 
 	// Load the new config and watch it for changes.
@@ -468,7 +469,7 @@ func TestWatchFile(t *testing.T) {
 
 	// Wait a second and change the file.
 	time.Sleep(1 * time.Second)
-	os.WriteFile(tmpFile, []byte(`{"parent": {"name": "name2"}}`), 0600)
+	ioutil.WriteFile(tmpFile, []byte(`{"parent": {"name": "name2"}}`), 0600) // TODO: replace with os.WriteFile as of go v1.16
 	wg.Wait()
 
 	assert.Condition(func() bool {
@@ -481,7 +482,7 @@ func TestWatchFileSymlink(t *testing.T) {
 		assert = assert.New(t)
 		k      = koanf.New(delim)
 	)
-	tmpDir := t.TempDir()
+	tmpDir, _ := ioutil.TempDir("", "koanf_*") // TODO: replace with t.TempDir() as of go v1.15
 
 	// Create a symlink.
 	symPath := filepath.Join(tmpDir, "koanf_test_symlink")