diff --git a/tests/psa-client-server/psasim/src/psa_sim_generate.pl b/tests/psa-client-server/psasim/src/psa_sim_generate.pl
index ee3894f0ee..baa060e344 100755
--- a/tests/psa-client-server/psasim/src/psa_sim_generate.pl
+++ b/tests/psa-client-server/psasim/src/psa_sim_generate.pl
@@ -242,6 +242,16 @@ EOF
 
     return ok ? PSA_SUCCESS : PSA_ERROR_GENERIC_ERROR;
 }
+EOF
+
+    # Finally, add psa_crypto_close()
+
+    print $fh <<EOF;
+
+void psa_crypto_close(void)
+{
+    psa_sim_serialize_reset();
+}
 EOF
 
     close($fh);