diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index c51bb8dad9..b7c891eb77 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -7061,7 +7061,7 @@ psa_status_t psa_key_derivation_input_key(
                                                slot->key.data,
                                                slot->key.bytes);
 
-    unlock_status = psa_unregister_read(slot);
+    unlock_status = psa_unregister_read_under_mutex(slot);
 
     return (status == PSA_SUCCESS) ? unlock_status : status;
 }
@@ -7218,7 +7218,7 @@ psa_status_t psa_key_derivation_key_agreement(psa_key_derivation_operation_t *op
         }
     }
 
-    unlock_status = psa_unregister_read(slot);
+    unlock_status = psa_unregister_read_under_mutex(slot);
 
     return (status == PSA_SUCCESS) ? unlock_status : status;
 }