diff --git a/rest/client_test.go b/rest/client_test.go
index 6b359aa7..6ba9e738 100644
--- a/rest/client_test.go
+++ b/rest/client_test.go
@@ -23,7 +23,6 @@ import (
 	"net/http/httptest"
 	"net/http/httputil"
 	"net/url"
-	"os"
 	"reflect"
 	"testing"
 	"time"
@@ -340,8 +339,8 @@ func TestCreateBackoffManager(t *testing.T) {
 	theUrl, _ := url.Parse("http://localhost")
 
 	// 1 second base backoff + duration of 2 seconds -> exponential backoff for requests.
-	os.Setenv(envBackoffBase, "1")
-	os.Setenv(envBackoffDuration, "2")
+	t.Setenv(envBackoffBase, "1")
+	t.Setenv(envBackoffDuration, "2")
 	backoff := readExpBackoffConfig()
 	backoff.UpdateBackoff(theUrl, nil, 500)
 	backoff.UpdateBackoff(theUrl, nil, 500)
@@ -350,8 +349,8 @@ func TestCreateBackoffManager(t *testing.T) {
 	}
 
 	// 0 duration -> no backoff.
-	os.Setenv(envBackoffBase, "1")
-	os.Setenv(envBackoffDuration, "0")
+	t.Setenv(envBackoffBase, "1")
+	t.Setenv(envBackoffDuration, "0")
 	backoff.UpdateBackoff(theUrl, nil, 500)
 	backoff.UpdateBackoff(theUrl, nil, 500)
 	backoff = readExpBackoffConfig()
@@ -360,8 +359,8 @@ func TestCreateBackoffManager(t *testing.T) {
 	}
 
 	// No env -> No backoff.
-	os.Setenv(envBackoffBase, "")
-	os.Setenv(envBackoffDuration, "")
+	t.Setenv(envBackoffBase, "")
+	t.Setenv(envBackoffDuration, "")
 	backoff = readExpBackoffConfig()
 	backoff.UpdateBackoff(theUrl, nil, 500)
 	backoff.UpdateBackoff(theUrl, nil, 500)
diff --git a/rest/connection_test.go b/rest/connection_test.go
index 323c9eec..8d705b78 100644
--- a/rest/connection_test.go
+++ b/rest/connection_test.go
@@ -24,7 +24,6 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"net/url"
-	"os"
 	"strconv"
 	"strings"
 	"sync/atomic"
@@ -80,23 +79,15 @@ func newLB(t *testing.T, serverURL string) *tcpLB {
 	return &lb
 }
 
-func setEnv(key, value string) func() {
-	originalValue := os.Getenv(key)
-	os.Setenv(key, value)
-	return func() {
-		os.Setenv(key, originalValue)
-	}
-}
-
 const (
 	readIdleTimeout int = 1
 	pingTimeout     int = 1
 )
 
 func TestReconnectBrokenTCP(t *testing.T) {
-	defer setEnv("HTTP2_READ_IDLE_TIMEOUT_SECONDS", strconv.Itoa(readIdleTimeout))()
-	defer setEnv("HTTP2_PING_TIMEOUT_SECONDS", strconv.Itoa(pingTimeout))()
-	defer setEnv("DISABLE_HTTP2", "")()
+	t.Setenv("HTTP2_READ_IDLE_TIMEOUT_SECONDS", strconv.Itoa(readIdleTimeout))
+	t.Setenv("HTTP2_PING_TIMEOUT_SECONDS", strconv.Itoa(pingTimeout))
+	t.Setenv("DISABLE_HTTP2", "")
 	ts := httptest.NewUnstartedServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		fmt.Fprintf(w, "Hello, %s", r.Proto)
 	}))
diff --git a/tools/clientcmd/loader_test.go b/tools/clientcmd/loader_test.go
index ba42e56f..aa6741b8 100644
--- a/tools/clientcmd/loader_test.go
+++ b/tools/clientcmd/loader_test.go
@@ -897,12 +897,9 @@ func TestLoadingGetLoadingPrecedence(t *testing.T) {
 		},
 	}
 
-	kubeconfig := os.Getenv("KUBECONFIG")
-	defer os.Setenv("KUBECONFIG", kubeconfig)
-
 	for name, test := range testCases {
 		t.Run(name, func(t *testing.T) {
-			os.Setenv("KUBECONFIG", test.env)
+			t.Setenv("KUBECONFIG", test.env)
 			rules := test.rules
 			if rules == nil {
 				rules = NewDefaultClientConfigLoadingRules()