diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index b9ea00f2c..e8ab01f63 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -1013,6 +1013,9 @@ psa_status_t psa_destroy_key( psa_key_handle_t handle )
     psa_se_drv_table_entry_t *driver;
 #endif /* MBEDTLS_PSA_CRYPTO_SE_C */
 
+    if( handle == 0 )
+        return( PSA_SUCCESS );
+
     status = psa_get_key_slot( handle, &slot );
     if( status != PSA_SUCCESS )
         return( status );
diff --git a/library/psa_crypto_slot_management.c b/library/psa_crypto_slot_management.c
index 59be319ce..6cd6a1135 100644
--- a/library/psa_crypto_slot_management.c
+++ b/library/psa_crypto_slot_management.c
@@ -255,6 +255,9 @@ psa_status_t psa_close_key( psa_key_handle_t handle )
     psa_status_t status;
     psa_key_slot_t *slot;
 
+    if( handle == 0 )
+        return( PSA_SUCCESS );
+
     status = psa_get_key_slot( handle, &slot );
     if( status != PSA_SUCCESS )
         return( status );