diff --git a/programs/cipher/cipher_aead_demo.c b/programs/cipher/cipher_aead_demo.c
index 05d1cb0..0cee51f 100644
--- a/programs/cipher/cipher_aead_demo.c
+++ b/programs/cipher/cipher_aead_demo.c
@@ -98,7 +98,9 @@
     printf( "\n" );
 }
 
-/* Run an Mbed TLS function and bail out if it fails. */
+/* Run an Mbed TLS function and bail out if it fails.
+ * A string description of the error code can be recovered with:
+ * programs/util/strerror <value> */
 #define CHK( expr )                                             \
     do                                                          \
     {                                                           \
diff --git a/programs/hash/md_hmac_demo.c b/programs/hash/md_hmac_demo.c
index 0f6495c..d4cc3cc 100644
--- a/programs/hash/md_hmac_demo.c
+++ b/programs/hash/md_hmac_demo.c
@@ -77,7 +77,9 @@
     printf( "\n" );
 }
 
-/* Run an Mbed TLS function and bail out if it fails. */
+/* Run an Mbed TLS function and bail out if it fails.
+ * A string description of the error code can be recovered with:
+ * programs/util/strerror <value> */
 #define CHK( expr )                                             \
     do                                                          \
     {                                                           \
diff --git a/programs/psa/aead_demo.c b/programs/psa/aead_demo.c
index ac7bf65..7a07d8b 100644
--- a/programs/psa/aead_demo.c
+++ b/programs/psa/aead_demo.c
@@ -100,7 +100,9 @@
     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                                                          \
     {                                                           \
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                                                          \
     {                                                           \