diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 8312c0750..a8f36745c 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -1000,6 +1000,13 @@ psa_status_t psa_wipe_key_slot( psa_key_slot_t *slot )
 {
     psa_status_t status = psa_remove_key_data_from_memory( slot );
 
+   /*
+    * As the return error code may not be handled in case of multiple errors,
+    * do our best to report an unexpected lock counter: if available call
+    * MBEDTLS_TEST_HOOK_TEST_ASSERT that may terminate execution (if called as
+    * part of the execution of a test suite this will stop the test suite
+    * execution).
+    */
     if( slot->lock_count != 1 )
     {
         MBEDTLS_TEST_HOOK_TEST_ASSERT( slot->lock_count == 1 );
diff --git a/library/psa_crypto_slot_management.c b/library/psa_crypto_slot_management.c
index cb10f6e06..49e6b873b 100644
--- a/library/psa_crypto_slot_management.c
+++ b/library/psa_crypto_slot_management.c
@@ -412,6 +412,13 @@ psa_status_t psa_unlock_key_slot( psa_key_slot_t *slot )
         return( PSA_SUCCESS );
     }
 
+   /*
+    * As the return error code may not be handled in case of multiple errors,
+    * do our best to report if the lock counter is equal to zero: if available
+    * call MBEDTLS_TEST_HOOK_TEST_ASSERT that may terminate execution (if called
+    * as part of the execution of a unit test suite this will stop the test
+    * suite execution).
+    */
     MBEDTLS_TEST_HOOK_TEST_ASSERT( slot->lock_count > 0 );
     return( PSA_ERROR_CORRUPTION_DETECTED );
 }