diff --git a/code/compiler/13/parse_driver.hpp b/code/compiler/13/parse_driver.hpp
index 580e250..3d8592b 100644
--- a/code/compiler/13/parse_driver.hpp
+++ b/code/compiler/13/parse_driver.hpp
@@ -29,6 +29,7 @@ struct parse_driver {
     void run_parse() {
         file_stream.open(file_name);
         if(!file_stream.good()) throw 0;
+        line_offsets.push_back(0);
         yyscan_t scanner;
         scanner_init(this, &scanner);
         yy::parser parser(scanner, *this);
@@ -47,15 +48,16 @@ struct parse_driver {
     }
 
     size_t get_index(int line, int column) {
-        assert(line-1 < line_offsets.size());
-        size_t file_offset = line ? 0 : line_offsets[line-1];
+        assert(line > 0);
+        assert(line <= line_offsets.size());
+        size_t file_offset = line_offsets[line-1];
         file_offset += column - 1;
         return file_offset;
     }
 
     size_t get_line_end(int line) {
-        assert(line < line_offsets.size());
-        return line_offsets[line] - 1;
+        if(line > line_offsets.size()) return read_file.size();
+        return get_index(line+1, 1);
     }
 };