diff --git a/include/polarssl/sha1.h b/include/polarssl/sha1.h
index 48da246..81ea77d 100644
--- a/include/polarssl/sha1.h
+++ b/include/polarssl/sha1.h
@@ -3,7 +3,7 @@
  *
  * \brief SHA-1 cryptographic hash function
  *
- *  Copyright (C) 2006-2010, Brainspark B.V.
+ *  Copyright (C) 2006-2013, Brainspark B.V.
  *
  *  This file is part of PolarSSL (http://www.polarssl.org)
  *  Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
@@ -27,6 +27,8 @@
 #ifndef POLARSSL_SHA1_H
 #define POLARSSL_SHA1_H
 
+#include "config.h"
+
 #include <string.h>
 
 #ifdef _MSC_VER
@@ -38,6 +40,10 @@
 
 #define POLARSSL_ERR_SHA1_FILE_IO_ERROR                -0x0076  /**< Read/write error in file. */
 
+#if !defined(POLARSSL_SHA1_ALT)
+// Regular implementation
+//
+
 /**
  * \brief          SHA-1 context structure
  */
@@ -80,6 +86,21 @@
  */
 void sha1_finish( sha1_context *ctx, unsigned char output[20] );
 
+/* Internal use */
+void sha1_process( sha1_context *ctx, const unsigned char data[64] );
+
+#ifdef __cplusplus
+}
+#endif
+
+#else  /* POLARSSL_SHA1_ALT */
+#include "sha1_alt.h"
+#endif /* POLARSSL_SHA1_ALT */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /**
  * \brief          Output = SHA-1( input buffer )
  *
@@ -152,9 +173,6 @@
  */
 int sha1_self_test( int verbose );
 
-/* Internal use */
-void sha1_process( sha1_context *ctx, const unsigned char data[64] );
-
 #ifdef __cplusplus
 }
 #endif