diff --git a/internal/command/command.go b/internal/command/command.go
index 9155751f47a24e7c5bd3e8c68c548ecbcca3304f..287fa6a7551bf4501bc152f820752953e30af6bb 100644
--- a/internal/command/command.go
+++ b/internal/command/command.go
@@ -197,7 +197,7 @@ func New(ctx context.Context, cmd *exec.Cmd, stdin io.Reader, stdout, stderr io.
 	env = append(env, "GIT_TERMINAL_PROMPT=0")
 
 	// Export env vars
-	cmd.Env = append(env, AllowedEnvironment(os.Environ())...)
+	cmd.Env = append(AllowedEnvironment(os.Environ()), env...)
 	cmd.Env = envInjector(ctx, cmd.Env)
 
 	// Start the command in its own process group (nice for signalling)
diff --git a/internal/command/command_test.go b/internal/command/command_test.go
index 08f51a97a0a089eccf19b6e174d56c765923e120..cc60394a3b0e4ac1fc675159d8a9af7bf19d28f2 100644
--- a/internal/command/command_test.go
+++ b/internal/command/command_test.go
@@ -91,18 +91,42 @@ func TestNewCommandProxyEnv(t *testing.T) {
 
 	for _, tc := range testCases {
 		t.Run(tc.key, func(t *testing.T) {
-			extraVar := fmt.Sprintf("%s=%s", tc.key, tc.value)
+			os.Setenv(tc.key, tc.value)
+			defer os.Unsetenv(tc.key)
+
 			buff := &bytes.Buffer{}
-			cmd, err := New(ctx, exec.Command("/usr/bin/env"), nil, buff, nil, extraVar)
+			cmd, err := New(ctx, exec.Command("/usr/bin/env"), nil, buff, nil)
 
 			require.NoError(t, err)
 			require.NoError(t, cmd.Wait())
 
+			extraVar := fmt.Sprintf("%s=%s", tc.key, tc.value)
 			require.Contains(t, strings.Split(buff.String(), "\n"), extraVar)
 		})
 	}
 }
 
+func TestPassedInEnvsTakeHigherPriority(t *testing.T) {
+	envValueOs := "foobar_os"
+	envValuePassedIn := "foobar_passed_in"
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	oldTZ := os.Getenv("TZ")
+	defer os.Setenv("TZ", oldTZ)
+
+	os.Setenv("TZ", envValueOs)
+
+	buff := &bytes.Buffer{}
+	cmd, err := New(ctx, exec.Command("env"), nil, buff, nil, "TZ="+envValuePassedIn)
+
+	require.NoError(t, err)
+	require.NoError(t, cmd.Wait())
+
+	require.Contains(t, strings.Split(buff.String(), "\n"), "TZ="+envValuePassedIn)
+}
+
 func TestRejectEmptyContextDone(t *testing.T) {
 	defer func() {
 		p := recover()