diff --git a/scripts/generate_psa_constants.py b/scripts/generate_psa_constants.py
index a9de148..c6bd9b6 100755
--- a/scripts/generate_psa_constants.py
+++ b/scripts/generate_psa_constants.py
@@ -61,7 +61,7 @@
     default:
         %(key_type_code)s{
             return snprintf(buffer, buffer_size,
-                            "0x%%08lx", (unsigned long) type);
+                            "0x%%04x", (unsigned) type);
         }
         break;
     }