diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
index 16c6e61c7e11..d6d993b436cb 100644
--- a/drivers/i2c/busses/i2c-stm32f7.c
+++ b/drivers/i2c/busses/i2c-stm32f7.c
@@ -464,8 +464,13 @@ static int stm32f7_i2c_compute_timing(struct stm32f7_i2c_dev *i2c_dev,
 {
 	struct stm32f7_i2c_spec *specs;
 	u32 p_prev = STM32F7_PRESC_MAX;
-	u32 i2cclk = DIV_ROUND_CLOSEST(NSEC_PER_SEC,
-				       setup->clock_src);
+	/*
+	 * Truncate instead of rounding to closest: if the clock period is
+	 * overestimated, the computed SCL timings will come out shorter on
+	 * the wire, which can push the bus above the target rate and below
+	 * the spec's tLOW/tHIGH minimums.
+	 */
+	u32 i2cclk = NSEC_PER_SEC / setup->clock_src;
 	u32 i2cbus = DIV_ROUND_CLOSEST(NSEC_PER_SEC,
 				       setup->speed_freq);
 	u32 clk_error_prev = i2cbus;