diff --git a/go.mod b/go.mod
index d00fa96..0ba7c4b 100644
--- a/go.mod
+++ b/go.mod
@@ -19,6 +19,6 @@ require (
 	github.com/yusufpapurcu/wmi v1.2.2 // indirect
 	go.uber.org/atomic v1.10.0 // indirect
 	go.uber.org/multierr v1.8.0 // indirect
-	golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab // indirect
+	golang.org/x/sys v0.0.0-20220817070843-5a390386f1f2 // indirect
 	google.golang.org/protobuf v1.28.1 // indirect
 )
diff --git a/go.sum b/go.sum
index 93c5c01..b68b5a2 100644
--- a/go.sum
+++ b/go.sum
@@ -42,8 +42,8 @@ go.uber.org/zap v1.22.0/go.mod h1:H4siCOZOrAolnUPJEkfaSjDqyP+BDS0DdDWzwcgt3+U=
 golang.org/x/sys v0.0.0-20190916202348-b4ddaad3f8a3/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20220128215802-99c3d69c2c27/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220503163025-988cb79eb6c6/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab h1:2QkjZIsXupsJbJIdSjjUOgWK3aEtzyuh2mPt3l/CkeU=
-golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20220817070843-5a390386f1f2 h1:fqTvyMIIj+HRzMmnzr9NtpHP6uVpvB5fkHcgPDC4nu8=
+golang.org/x/sys v0.0.0-20220817070843-5a390386f1f2/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 google.golang.org/protobuf v1.26.0-rc.1/go.mod h1:jlhhOSvTdKEhbULTjvd4ARK9grFBp09yW+WbY/TyQbw=
diff --git a/process.go b/process.go
index 855ad50..0e9f9ca 100644
--- a/process.go
+++ b/process.go
@@ -147,7 +147,7 @@ func (p *Process) setEnv(e Env) []string {
 	env := make([]string, 0, len(os.Environ())+len(e))
 	env = append(env, os.Environ()...)
 	for k, v := range e {
-		env = append(env, fmt.Sprintf("%s=%s", k, os.Expand(v, os.Getenv)))
+		env = append(env, fmt.Sprintf("%s=%s", strings.ToUpper(k), os.Expand(v, os.Getenv)))
 	}
 	return env
 }
diff --git a/process_test.go b/process_test.go
index 2a92489..bc924f0 100644
--- a/process_test.go
+++ b/process_test.go
@@ -14,11 +14,11 @@ func TestSetEnv(t *testing.T) {
 	val := out[len(out)-1]
 	val2 := out[len(out)-2]
 
-	if val != "bar=baz" && val != "foo=bar" {
+	if val != "BAR=baz" && val != "FOO=bar" {
 		t.Fail()
 	}
 
-	if val2 != "bar=baz" && val2 != "foo=bar" {
+	if val2 != "BAR=baz" && val2 != "FOO=bar" {
 		t.Fail()
 	}
 }