diff --git a/drivers/iio/adc/max9611.c b/drivers/iio/adc/max9611.c
index da073d72f649..e480529b3f04 100644
--- a/drivers/iio/adc/max9611.c
+++ b/drivers/iio/adc/max9611.c
@@ -89,6 +89,12 @@
 #define MAX9611_TEMP_SCALE_NUM		1000000
 #define MAX9611_TEMP_SCALE_DIV		2083
 
+/*
+ * Conversion time is 2 ms (typically) at Ta=25 degreeC
+ * No maximum value is known, so play it safe.
+ */
+#define MAX9611_CONV_TIME_US_RANGE	3000, 3300
+
 struct max9611_dev {
 	struct device *dev;
 	struct i2c_client *i2c_client;
@@ -236,11 +242,9 @@ static int max9611_read_single(struct max9611_dev *max9611,
 		return ret;
 	}
 
-	/*
-	 * need a delay here to make register configuration
-	 * stabilize. 1 msec at least, from empirical testing.
-	 */
-	usleep_range(1000, 2000);
+	/* need a delay here to make register configuration stabilize. */
+
+	usleep_range(MAX9611_CONV_TIME_US_RANGE);
 
 	ret = i2c_smbus_read_word_swapped(max9611->i2c_client, reg_addr);
 	if (ret < 0) {
@@ -507,7 +511,7 @@ static int max9611_init(struct max9611_dev *max9611)
 			MAX9611_REG_CTRL2, 0);
 		return ret;
 	}
-	usleep_range(1000, 2000);
+	usleep_range(MAX9611_CONV_TIME_US_RANGE);
 
 	return 0;
 }