diff --git a/include/mbedtls/sha512.h b/include/mbedtls/sha512.h
index 8404a2d..c4eb5a9 100644
--- a/include/mbedtls/sha512.h
+++ b/include/mbedtls/sha512.h
@@ -35,14 +35,14 @@
 
 #define MBEDTLS_ERR_SHA512_HW_ACCEL_FAILED                -0x0039  /**< SHA-512 hardware accelerator failed */
 
-#if !defined(MBEDTLS_SHA512_ALT)
-// Regular implementation
-//
-
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+#if !defined(MBEDTLS_SHA512_ALT)
+// Regular implementation
+//
+
 /**
  * \brief          The SHA-512 context structure.
  *
@@ -61,6 +61,10 @@
 }
 mbedtls_sha512_context;
 
+#else  /* MBEDTLS_SHA512_ALT */
+#include "sha512_alt.h"
+#endif /* MBEDTLS_SHA512_ALT */
+
 /**
  * \brief          This function initializes a SHA-512 context.
  *
@@ -198,18 +202,6 @@
 #undef MBEDTLS_DEPRECATED
 #endif /* !MBEDTLS_DEPRECATED_REMOVED */
 
-#ifdef __cplusplus
-}
-#endif
-
-#else  /* MBEDTLS_SHA512_ALT */
-#include "sha512_alt.h"
-#endif /* MBEDTLS_SHA512_ALT */
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 /**
  * \brief          This function calculates the SHA-512 or SHA-384
  *                 checksum of a buffer.