diff --git a/include/zh_pcf8574.h b/include/zh_pcf8574.h
index 5849c67..2d90f8e 100755
--- a/include/zh_pcf8574.h
+++ b/include/zh_pcf8574.h
@@ -26,6 +26,7 @@
         .task_priority = 1,                          \
         .stack_size = configMINIMAL_STACK_SIZE,      \
         .i2c_address = 0xFF,                         \
+        .i2c_frequency = 100000,                     \
         .p0_gpio_work_mode = ZH_PCF8574_GPIO_OUTPUT, \
         .p1_gpio_work_mode = ZH_PCF8574_GPIO_OUTPUT, \
         .p2_gpio_work_mode = ZH_PCF8574_GPIO_OUTPUT, \
@@ -65,6 +66,7 @@ extern "C"
     typedef struct
     {
         i2c_master_bus_handle_t i2c_handle; /*!< Unique I2C bus handle. @attention Must be same for all PCF8574 expanders. */
+        uint32_t i2c_frequency;             /*!< Expander I2C frequency. */
         uint16_t stack_size;                /*!< Stack size for task for the PCF8574 expander isr processing processing. @note The minimum size is configMINIMAL_STACK_SIZE. */
         uint8_t task_priority;              /*!< Task priority for the PCF8574 expander isr processing. @note Minimum value is 1. */
         uint8_t i2c_address;                /*!< Expander I2C address. */
diff --git a/version.txt b/version.txt
index 914ec96..9aa3464 100644
--- a/version.txt
+++ b/version.txt
@@ -1 +1 @@
-2.6.0
\ No newline at end of file
+2.7.0
\ No newline at end of file
diff --git a/zh_pcf8574.c b/zh_pcf8574.c
index e8aea04..2839aba 100755
--- a/zh_pcf8574.c
+++ b/zh_pcf8574.c
@@ -224,6 +224,7 @@ void zh_pcf8574_reset_stats(void)
 static esp_err_t _zh_pcf8574_validate_config(const zh_pcf8574_init_config_t *config) // -V2008
 {
     ZH_ERROR_CHECK((config->i2c_address >= 0x20 && config->i2c_address <= 0x27) || (config->i2c_address >= 0x38 && config->i2c_address <= 0x3F), ESP_ERR_INVALID_ARG, NULL, "Invalid I2C address.");
+    ZH_ERROR_CHECK(config->i2c_frequency <= 100000, ESP_ERR_INVALID_ARG, NULL, "Invalid I2C frequency.");
     ZH_ERROR_CHECK(config->task_priority >= 1 && config->stack_size >= configMINIMAL_STACK_SIZE, ESP_ERR_INVALID_ARG, NULL, "Invalid task settings.");
     ZH_ERROR_CHECK(config->interrupt_gpio <= GPIO_NUM_MAX, ESP_ERR_INVALID_ARG, NULL, "Invalid GPIO number.");
     ZH_ERROR_CHECK(config->i2c_handle != NULL, ESP_ERR_INVALID_ARG, NULL, "Invalid I2C handle.");
@@ -279,7 +280,7 @@ static esp_err_t _zh_pcf8574_i2c_init(const zh_pcf8574_init_config_t *config, zh
     i2c_device_config_t pcf8574_config = {
         .dev_addr_length = I2C_ADDR_BIT_LEN_7,
         .device_address = config->i2c_address,
-        .scl_speed_hz = 100000,
+        .scl_speed_hz = config->i2c_frequency,
     };
     i2c_master_dev_handle_t _dev_handle = NULL;
     esp_err_t err = i2c_master_bus_add_device(config->i2c_handle, &pcf8574_config, &_dev_handle);