diff --git a/library/sha2.c b/library/sha2.c
index 64ebc43..385c048 100644
--- a/library/sha2.c
+++ b/library/sha2.c
@@ -34,7 +34,9 @@
 
 #include "polarssl/sha2.h"
 
+#if defined(POLARSSL_FS_IO) || defined(POLARSSL_SELF_TEST)
 #include <stdio.h>
+#endif
 
 /*
  * 32-bit integer manipulation macros (big endian)
@@ -327,6 +329,7 @@
     memset( &ctx, 0, sizeof( sha2_context ) );
 }
 
+#if defined(POLARSSL_FS_IO)
 /*
  * output = SHA-256( file contents )
  */
@@ -358,6 +361,7 @@
     fclose( f );
     return( 0 );
 }
+#endif /* POLARSSL_FS_IO */
 
 /*
  * SHA-256 HMAC context setup