diff --git a/programs/psa/hmac_demo.c b/programs/psa/hmac_demo.c
index 3cb0d21..c6c320b 100644
--- a/programs/psa/hmac_demo.c
+++ b/programs/psa/hmac_demo.c
@@ -79,7 +79,9 @@
     printf( "\n" );
 }
 
-/* Run a PSA function and bail out if it fails. */
+/* Run a PSA function and bail out if it fails.
+ * The symbolic name of the error code can be recovered using:
+ * programs/psa/psa_consant_name status <value> */
 #define PSA_CHECK( expr )                                       \
     do                                                          \
     {                                                           \