diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 733a2e4..0ac6290 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -420,6 +420,7 @@
             *bits = 448;
             return( PSA_ECC_CURVE_MONTGOMERY );
         default:
+            *bits = 0;
             return( 0 );
     }
 }