diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index 21aa70a..d03e30a 100644
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -299,7 +299,7 @@ u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
 	acpi_status status;
 	struct acpi_object_list input;
 	union acpi_object params[3];
-	char method[4] = "WM";
+	char method[5] = "WM";
 
 	if (!find_guid(guid_string, &wblock))
 		return AE_ERROR;
@@ -357,8 +357,8 @@ struct acpi_buffer *out)
 	acpi_status status, wc_status = AE_ERROR;
 	struct acpi_object_list input, wc_input;
 	union acpi_object wc_params[1], wq_params[1];
-	char method[4];
-	char wc_method[4] = "WC";
+	char method[5];
+	char wc_method[5] = "WC";
 
 	if (!guid_string || !out)
 		return AE_BAD_PARAMETER;
@@ -439,7 +439,7 @@ const struct acpi_buffer *in)
 	acpi_handle handle;
 	struct acpi_object_list input;
 	union acpi_object params[2];
-	char method[4] = "WS";
+	char method[5] = "WS";
 
 	if (!guid_string || !in)
 		return AE_BAD_DATA;