diff --git a/components/zdevice/include/boreas/gpio_dt.h b/components/zdevice/include/boreas/gpio_dt.h
index 89d2b4d..f1477da 100644
--- a/components/zdevice/include/boreas/gpio_dt.h
+++ b/components/zdevice/include/boreas/gpio_dt.h
@@ -16,6 +16,9 @@
 /* Bits 0-7: dt_flags — board-level properties (uint8_t in gpio_dt_spec).
  * Bit positions match upstream Zephyr dt-bindings/gpio/gpio.h. */
 #define GPIO_ACTIVE_LOW  BIT(0)
+/* Named zero: active-high is the absence of the active-low bit. Mirrors
+ * upstream's GPIO_ACTIVE_HIGH so boards/devicetree can state intent explicitly. */
+#define GPIO_ACTIVE_HIGH (0 << 0)
 #define GPIO_OPEN_DRAIN  BIT(1) /* reserved */
 #define GPIO_OPEN_SOURCE BIT(2) /* reserved */
 #define GPIO_PULL_UP     BIT(4)
diff --git a/test/main/test_gpio_flags.c b/test/main/test_gpio_flags.c
index 13faa57..45ab27a 100644
--- a/test/main/test_gpio_flags.c
+++ b/test/main/test_gpio_flags.c
@@ -230,6 +230,23 @@ static void test_gpio_set_dt_no_invert_active_high(void)
 	TEST_ASSERT_EQUAL(0, last_set_raw_value);
 }
 
+static void test_gpio_active_high_is_named_zero(void)
+{
+	/* GPIO_ACTIVE_HIGH is the named absence of the active-low bit, so a spec
+	 * declared with it must behave identically to dt_flags == 0. */
+	TEST_ASSERT_EQUAL(0, GPIO_ACTIVE_HIGH);
+
+	reset_mock();
+	const struct gpio_dt_spec spec = {
+		.port = &mock_gpio, .pin = 4, .dt_flags = GPIO_ACTIVE_HIGH};
+
+	gpio_pin_set_dt(&spec, 1);
+	TEST_ASSERT_EQUAL(1, last_set_raw_value);
+
+	gpio_pin_set_dt(&spec, 0);
+	TEST_ASSERT_EQUAL(0, last_set_raw_value);
+}
+
 static void test_gpio_get_dt_inverts_for_active_low(void)
 {
 	reset_mock();
@@ -257,5 +274,6 @@ void test_gpio_flags_group(void)
 	RUN_TEST(test_gpio_active_low_stripped_from_driver_flags);
 	RUN_TEST(test_gpio_set_dt_inverts_for_active_low);
 	RUN_TEST(test_gpio_set_dt_no_invert_active_high);
+	RUN_TEST(test_gpio_active_high_is_named_zero);
 	RUN_TEST(test_gpio_get_dt_inverts_for_active_low);
 }