diff --git a/chip/lm4/adc.c b/chip/lm4/adc.c
index e58945605e..f797317688 100644
--- a/chip/lm4/adc.c
+++ b/chip/lm4/adc.c
@@ -18,6 +18,9 @@
 #include "timer.h"
 #include "util.h"
 
+/* Maximum time we allow for an ADC conversion */
+#define ADC_TIMEOUT_US SECOND
+
 static task_id_t task_waiting_on_ss[LM4_ADC_SEQ_COUNT];
 
 static void configure_gpio(void)
@@ -74,13 +77,21 @@ static int flush_and_read(enum lm4_adc_sequencer seq)
 	/* Clear the interrupt status */
 	LM4_ADC_ADCISC |= 0x01 << seq;
 
+	/* Enable interrupt */
+	LM4_ADC_ADCIM |= 0x01 << seq;
+
 	/* Initiate sample sequence */
 	LM4_ADC_ADCPSSI |= 0x01 << seq;
 
 	/* Wait for interrupt */
-	event = task_wait_event(SECOND);
+	event = task_wait_event_mask(TASK_EVENT_ADC_DONE, ADC_TIMEOUT_US);
+
+	/* Disable interrupt */
+	LM4_ADC_ADCIM &= ~(0x01 << seq);
+
 	task_waiting_on_ss[seq] = TASK_ID_INVALID;
-	if (event == TASK_EVENT_TIMER)
+
+	if (!(event & TASK_EVENT_ADC_DONE))
 		return ADC_READ_ERROR;
 
 	/* Read the FIFO and convert to temperature */
@@ -159,6 +170,7 @@ int adc_read_channel(enum adc_channel ch)
 
 	if (rv == ADC_READ_ERROR)
 		return ADC_READ_ERROR;
+
 	return rv * adc->factor_mul / adc->factor_div + adc->shift;
 }
 
@@ -189,7 +201,7 @@ static void handle_interrupt(int ss)
 
 	/* Wake up the task which was waiting on the interrupt, if any */
 	if (id != TASK_ID_INVALID)
-		task_wake(id);
+		task_set_event(id, TASK_EVENT_ADC_DONE, 0);
 }
 
 void ss0_interrupt(void) { handle_interrupt(0); }
@@ -255,8 +267,7 @@ static void adc_init(void)
 	for (i = 0; i < LM4_ADC_SEQ_COUNT; i++)
 		task_waiting_on_ss[i] = TASK_ID_INVALID;
 
-	/* Enable interrupt */
-	LM4_ADC_ADCIM = 0xF;
+	/* Enable IRQs */
 	task_enable_irq(LM4_IRQ_ADC0_SS0);
 	task_enable_irq(LM4_IRQ_ADC0_SS1);
 	task_enable_irq(LM4_IRQ_ADC0_SS2);
diff --git a/include/task.h b/include/task.h
index 6b10c649b1..00368fbc34 100644
--- a/include/task.h
+++ b/include/task.h
@@ -13,7 +13,9 @@
 
 /* Task event bitmasks */
 /* Tasks may use the bits in TASK_EVENT_CUSTOM for their own events */
-#define TASK_EVENT_CUSTOM(x)	(x & 0x0fffffff)
+#define TASK_EVENT_CUSTOM(x)	(x & 0x07ffffff)
+/* ADC interrupt handler event */
+#define TASK_EVENT_ADC_DONE	(1 << 27)
 /* I2C interrupt handler event */
 #define TASK_EVENT_I2C_IDLE	(1 << 28)
 /* task_wake() called on task */