diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 66c8f65..9640687 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -2948,8 +2948,7 @@
     {
         switch( alg )
         {
-            case PSA_ALG_ARC4:
-            case PSA_ALG_CHACHA20:
+            case PSA_ALG_STREAM_CIPHER:
                 mode = MBEDTLS_MODE_STREAM;
                 break;
             case PSA_ALG_CTR: