diff --git a/include/libopencm3/stm32/common/i2c_common_v2.h b/include/libopencm3/stm32/common/i2c_common_v2.h
index 7f99cb05..1ee67984 100644
--- a/include/libopencm3/stm32/common/i2c_common_v2.h
+++ b/include/libopencm3/stm32/common/i2c_common_v2.h
@@ -393,7 +393,6 @@ void i2c_send_stop(uint32_t i2c);
 void i2c_clear_stop(uint32_t i2c);
 void i2c_set_own_7bit_slave_address(uint32_t i2c, uint8_t slave);
 void i2c_set_own_10bit_slave_address(uint32_t i2c, uint16_t slave);
-void i2c_set_clock_frequency(uint32_t i2c, uint8_t freq);
 void i2c_send_data(uint32_t i2c, uint8_t data);
 uint8_t i2c_get_data(uint32_t i2c);