diff --git a/tests/scripts/generate_psa_wrappers.py b/tests/scripts/generate_psa_wrappers.py
index d7970c0..c0ddebb 100755
--- a/tests/scripts/generate_psa_wrappers.py
+++ b/tests/scripts/generate_psa_wrappers.py
@@ -153,6 +153,9 @@
         # Proof-of-concept: just instrument one function for now
         if function_name == 'psa_cipher_encrypt':
             return True
+        if function_name in ('psa_key_derivation_output_bytes',
+                             'psa_key_derivation_input_bytes'):
+            return True
         if function_name in ('psa_import_key',
                              'psa_export_key',
                              'psa_export_public_key'):