--- a/src/lib_binary_dict_parser.cpp
+++ b/src/lib_binary_dict_parser.cpp
@@ -33,7 +33,7 @@
 /* Limit the initially reserved index size.
  * .ifo file may contain incorrect, unreasonably large value of index size,
  * so we'd be out of memory if we try to allocate such amount. */
-const size_t MAX_RESERVED_INDEX_SIZE = 200*1024;
+const guint32 MAX_RESERVED_INDEX_SIZE = 200*1024;
 
 static bool compare_worditem_by_offset(const worditem_t* left, const worditem_t* right)
 {