diff --git a/devicemodel/hw/platform/acpi/acpi.c b/devicemodel/hw/platform/acpi/acpi.c
index cec1d30cc..e5a392a32 100644
--- a/devicemodel/hw/platform/acpi/acpi.c
+++ b/devicemodel/hw/platform/acpi/acpi.c
@@ -850,6 +850,7 @@ dsdt_line(const char *fmt, ...)
 	return;
 
 err_exit:
+	va_end(ap);
 	dsdt_error = -1;
 }