diff --git a/runtime/adainclude/interfaces-rp2040.ads b/runtime/adainclude/interfaces-rp2040.ads
index 01ced5e..7ae68c8 100644
--- a/runtime/adainclude/interfaces-rp2040.ads
+++ b/runtime/adainclude/interfaces-rp2040.ads
@@ -1,10 +1,11 @@
 with System;
 
-package Interfaces.RP2040 is
+package Interfaces.RP2040
+   with Pure is
 
-   ROM_Base : constant System.Address := 
+   ROM_Base : constant System.Address :=
      System'To_Address (16#00000000#);
-   
+
    XIP_Base : constant System.Address :=
      System'To_Address (16#10000000#);