diff -rup flex-2.5.39/flex.skl flex-2.5.39-new/flex.skl
--- flex-2.5.39/flex.skl	2014-03-26 05:46:44.000000000 -0700
+++ flex-2.5.39-new/flex.skl	2016-10-13 14:59:20.568519189 -0700
@@ -1664,7 +1664,7 @@ int yyFlexLexer::yy_get_next_buffer()
 
 	else
 		{
-			yy_size_t num_to_read =
+			int num_to_read =
 			YY_CURRENT_BUFFER_LVALUE->yy_buf_size - number_to_move - 1;
 
 		while ( num_to_read <= 0 )
@@ -1715,7 +1715,7 @@ m4_ifdef( [[M4_YY_USES_REJECT]],
 
 		/* Read in more data. */
 		YY_INPUT( (&YY_CURRENT_BUFFER_LVALUE->yy_ch_buf[number_to_move]),
-			YY_G(yy_n_chars), num_to_read );
+			YY_G(yy_n_chars), (yy_size_t) num_to_read );
 
 		YY_CURRENT_BUFFER_LVALUE->yy_n_chars = YY_G(yy_n_chars);
 		}