diff --git a/drivers/acpi/apei/erst.c b/drivers/acpi/apei/erst.c
index bf65e3461531..15ab797641cf 100644
--- a/drivers/acpi/apei/erst.c
+++ b/drivers/acpi/apei/erst.c
@@ -108,7 +108,7 @@ static inline u64 erst_get_timeout(void)
 
 	if (erst_erange.attr & ERST_RANGE_SLOW) {
 		timeout = ((erst_erange.timings & ERST_EXEC_TIMING_MAX_MASK) >>
-			ERST_EXEC_TIMING_MAX_SHIFT) * NSEC_PER_MSEC;
+			ERST_EXEC_TIMING_MAX_SHIFT) * NSEC_PER_USEC;
 		if (timeout < FIRMWARE_TIMEOUT)
 			timeout = FIRMWARE_TIMEOUT;
 	}