diff --git a/include/mbedtls/aria.h b/include/mbedtls/aria.h
index 7dd960f..e984147 100644
--- a/include/mbedtls/aria.h
+++ b/include/mbedtls/aria.h
@@ -51,14 +51,14 @@
 
 #define MBEDTLS_ERR_ARIA_INVALID_INPUT_LENGTH -0x005E /**< Invalid data input length. */
 
-#if !defined(MBEDTLS_ARIA_ALT)
-// Regular implementation
-//
-
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+#if !defined(MBEDTLS_ARIA_ALT)
+// Regular implementation
+//
+
 /**
  * \brief The ARIA context-type definition.
  */