diff --git a/firmware/target/arm/s5l8700/adc-s5l8700.c b/firmware/target/arm/s5l8700/adc-s5l8700.c
index 4407334099..f979a9d54f 100644
--- a/firmware/target/arm/s5l8700/adc-s5l8700.c
+++ b/firmware/target/arm/s5l8700/adc-s5l8700.c
@@ -64,7 +64,7 @@ unsigned short adc_read(int channel)
     wakeup_wait(&adc_wakeup, TIMEOUT_BLOCK);
     
     /* get the converted data */
-    data = ADCDAT0;
+    data = ADCDAT0 & 0x3FF;
     
     /* put ADC back into standby */
     ADCCON |= (1 << 2);