diff --git a/library/aes.c b/library/aes.c
index 9dc7b7d..f91d251 100644
--- a/library/aes.c
+++ b/library/aes.c
@@ -1064,14 +1064,13 @@
 #endif
 
 #if !defined(MBEDTLS_AES_USE_HARDWARE_ONLY)
-    if (mode == MBEDTLS_AES_ENCRYPT) {
-        return mbedtls_internal_aes_encrypt(ctx, input, output);
-    } else {
 #if !defined(MBEDTLS_BLOCK_CIPHER_NO_DECRYPT)
+    if (mode == MBEDTLS_AES_DECRYPT) {
         return mbedtls_internal_aes_decrypt(ctx, input, output);
-#else
-        return MBEDTLS_ERR_AES_FEATURE_UNAVAILABLE;
+    } else
 #endif
+    {
+        return mbedtls_internal_aes_encrypt(ctx, input, output);
     }
 #endif /* !MBEDTLS_AES_USE_HARDWARE_ONLY */
 }