diff --git a/library/sha1.c b/library/sha1.c
index b65ab24..56028fe 100644
--- a/library/sha1.c
+++ b/library/sha1.c
@@ -344,7 +344,7 @@
     sha1_starts( &ctx );
 
     while( ( n = fread( buf, 1, sizeof( buf ), f ) ) > 0 )
-        sha1_update( &ctx, buf, (int) n );
+        sha1_update( &ctx, buf, n );
 
     sha1_finish( &ctx, output );