diff --git a/common/i2c.c b/common/i2c.c
index a17edc51d4..c3c8d50a9c 100644
--- a/common/i2c.c
+++ b/common/i2c.c
@@ -56,15 +56,18 @@ void i2c_lock(int port, int lock)
 	ASSERT(port != -1);
 #endif
 	if (lock) {
-		/* Don't allow deep sleep when I2C port is locked */
-		disable_sleep(SLEEP_MASK_I2C);
+		/*
+		 * Don't allow deep sleep when I2C port is locked
+		 * TODO(crbug.com/537759): Fix sleep mask for multi-port lock.
+		 */
+		disable_sleep(SLEEP_MASK_I2C_MASTER);
 
 		mutex_lock(port_mutex + port);
 	} else {
 		mutex_unlock(port_mutex + port);
 
 		/* Allow deep sleep again after I2C port is unlocked */
-		enable_sleep(SLEEP_MASK_I2C);
+		enable_sleep(SLEEP_MASK_I2C_MASTER);
 	}
 }
 
diff --git a/include/system.h b/include/system.h
index e6e585ba21..2a1c1784ca 100644
--- a/include/system.h
+++ b/include/system.h
@@ -294,13 +294,14 @@ enum {
 	/*
 	 * Sleep masks to prevent going in to deep sleep.
 	 */
-	SLEEP_MASK_AP_RUN   = (1 << 0), /* the main CPU is running */
-	SLEEP_MASK_UART     = (1 << 1), /* UART communication on-going */
-	SLEEP_MASK_I2C      = (1 << 2), /* I2C master communication on-going */
-	SLEEP_MASK_CHARGING = (1 << 3), /* Charging loop on-going */
-	SLEEP_MASK_USB_PWR  = (1 << 4), /* USB power loop on-going */
-	SLEEP_MASK_USB_PD   = (1 << 5), /* USB PD device connected */
-	SLEEP_MASK_SPI      = (1 << 6), /* SPI communications on-going */
+	SLEEP_MASK_AP_RUN     = (1 << 0), /* the main CPU is running */
+	SLEEP_MASK_UART       = (1 << 1), /* UART communication ongoing */
+	SLEEP_MASK_I2C_MASTER = (1 << 2), /* I2C master communication ongoing */
+	SLEEP_MASK_CHARGING   = (1 << 3), /* Charging loop ongoing */
+	SLEEP_MASK_USB_PWR    = (1 << 4), /* USB power loop ongoing */
+	SLEEP_MASK_USB_PD     = (1 << 5), /* USB PD device connected */
+	SLEEP_MASK_SPI        = (1 << 6), /* SPI communications ongoing */
+	SLEEP_MASK_I2C_SLAVE  = (1 << 7), /* I2C slave communication ongoing */
 
 	SLEEP_MASK_FORCE_NO_DSLEEP    = (1 << 15), /* Force disable. */