diff --git a/drivers/acpi/executer/exconvrt.c b/drivers/acpi/executer/exconvrt.c
index 97856c4..2133162 100644
--- a/drivers/acpi/executer/exconvrt.c
+++ b/drivers/acpi/executer/exconvrt.c
@@ -367,7 +367,7 @@
 
 		/* hex_length: 2 ascii hex chars per data byte */
 
-		hex_length = ACPI_MUL_2 (data_width);
+		hex_length = (acpi_native_uint) ACPI_MUL_2 (data_width);
 		for (i = 0, j = (hex_length-1); i < hex_length; i++, j--) {
 			/* Get one hex digit, most significant digits first */