diff --git a/src/mainboard/google/reef/variants/baseboard/devicetree.cb b/src/mainboard/google/reef/variants/baseboard/devicetree.cb
index 559b0071be..5aa1d32ec2 100644
--- a/src/mainboard/google/reef/variants/baseboard/devicetree.cb
+++ b/src/mainboard/google/reef/variants/baseboard/devicetree.cb
@@ -84,6 +84,17 @@ chip soc/intel/apollolake
 		}
 	}"
 
+	# Limit trackpad speed to 400kHz with manually tuned values.
+	register "i2c[4]" = "{
+		.speed = I2C_SPEED_FAST,
+		.speed_config[0] = {
+			.speed = I2C_SPEED_FAST,
+			.scl_lcnt = 0xd0,
+			.scl_hcnt = 0x68,
+			.sda_hold = 0x27,
+		}
+	}"
+
 	# Minimum SLP S3 assertion width 28ms.
 	register "slp_s3_assertion_width_usecs" = "28000"