diff --git a/library/pk.c b/library/pk.c
index 631415c..6706344 100644
--- a/library/pk.c
+++ b/library/pk.c
@@ -593,6 +593,9 @@
                                psa_algorithm_t hash_alg )
 {
 #if !defined(MBEDTLS_ECP_C)
+    ((void) pk);
+    ((void) handle);
+    ((void) hash_alg);
     return( MBEDTLS_ERR_PK_TYPE_MISMATCH );
 #else
     const mbedtls_ecp_keypair *ec;