diff --git a/library/aesce.c b/library/aesce.c
index 9a82731..b786563 100644
--- a/library/aesce.c
+++ b/library/aesce.c
@@ -248,6 +248,8 @@
     if (mode == MBEDTLS_AES_DECRYPT) {
         block = aesce_decrypt_block(block, keys, ctx->nr);
     } else
+#else
+    (void) mode;
 #endif
     {
         block = aesce_encrypt_block(block, keys, ctx->nr);