diff --git a/core/esp_iomux.c b/core/esp_iomux.c
index 414da19..7a4a95f 100644
--- a/core/esp_iomux.c
+++ b/core/esp_iomux.c
@@ -7,8 +7,8 @@
 #include "esp/iomux.h"
 #include "common_macros.h"
 
-const static IRAM_DATA uint32_t IOMUX_TO_GPIO[] = { 12, 13, 14, 15, 3, 1, 6, 7, 8, 9, 10, 11, 0, 2, 4, 5 };
-const static IRAM_DATA uint32_t GPIO_TO_IOMUX[] = { 12, 5, 13, 4, 14, 15, 6, 7, 8, 9, 10, 11, 0, 1, 2, 3 };
+const static IRAM_DATA uint8_t IOMUX_TO_GPIO[] = { 12, 13, 14, 15, 3, 1, 6, 7, 8, 9, 10, 11, 0, 2, 4, 5 };
+const static IRAM_DATA uint8_t GPIO_TO_IOMUX[] = { 12, 5, 13, 4, 14, 15, 6, 7, 8, 9, 10, 11, 0, 1, 2, 3 };
 
 uint8_t IRAM gpio_to_iomux(const uint8_t gpio_number)
 {