diff --git a/library/aes.c b/library/aes.c
index aaea70b..203db0d 100644
--- a/library/aes.c
+++ b/library/aes.c
@@ -981,6 +981,7 @@
  */
 MBEDTLS_MAYBE_UNUSED static void aes_maybe_realign(mbedtls_aes_context *ctx)
 {
+#if defined(MAY_NEED_TO_ALIGN)
     unsigned new_offset = mbedtls_aes_rk_offset(ctx->buf);
     if (new_offset != ctx->rk_offset) {
         memmove(ctx->buf + new_offset,     // new address
@@ -988,6 +989,8 @@
                 (ctx->nr + 1) * 16);       // number of round keys * bytes per rk
         ctx->rk_offset = new_offset;
     }
+#endif /* MAY_NEED_TO_ALIGN */
+    (void) ctx;
 }
 
 /*