diff --git a/programs/ssl/ssl_test_lib.c b/programs/ssl/ssl_test_lib.c
index c0704d0..7eebebb 100644
--- a/programs/ssl/ssl_test_lib.c
+++ b/programs/ssl/ssl_test_lib.c
@@ -221,6 +221,7 @@
     return 0;
 }
 
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
 int key_opaque_set_alg_usage( const char *alg1, const char *alg2,
                               psa_algorithm_t *psa_alg1,
                               psa_algorithm_t *psa_alg2,
@@ -284,6 +285,7 @@
 
     return 0;
 }
+#endif /* MBEDTLS_USE_PSA_CRYPTO */
 
 #if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK)
 int ca_callback( void *data, mbedtls_x509_crt const *child,
diff --git a/programs/ssl/ssl_test_lib.h b/programs/ssl/ssl_test_lib.h
index 618da51..367b8e2 100644
--- a/programs/ssl/ssl_test_lib.h
+++ b/programs/ssl/ssl_test_lib.h
@@ -240,6 +240,7 @@
  */
 int key_opaque_alg_parse( const char *arg, const char **alg1, const char **alg2 );
 
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
 /** Parse given opaque key algoritms to obtain psa algs and usage
  *  that will be passed to mbedtls_pk_wrap_as_opaque().
  *
@@ -257,6 +258,7 @@
                               psa_algorithm_t *psa_alg1,
                               psa_algorithm_t *psa_alg2,
                               psa_key_usage_t *usage );
+#endif /* MBEDTLS_USE_PSA_CRYPTO */
 
 #if defined(MBEDTLS_USE_PSA_CRYPTO) && defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)
 /* The test implementation of the PSA external RNG is insecure. When