diff --git a/include/polarssl/sha2.h b/include/polarssl/sha2.h
index 811b0fd..da3970c 100644
--- a/include/polarssl/sha2.h
+++ b/include/polarssl/sha2.h
@@ -153,6 +153,9 @@
  */
 int sha2_self_test( int verbose );
 
+/* Internal use */
+void sha2_process( sha2_context *ctx, const unsigned char data[64] );
+
 #ifdef __cplusplus
 }
 #endif