1 files changed, 5 insertions, 1 deletions

diff --git a/lstring.h b/lstring.h
index 56896867..a413a9d3 100644
--- a/lstring.h
+++ b/lstring.h
@@ -19,7 +19,11 @@
 #define MEMERRMSG       "not enough memory"
 
 
-#define sizelstring(l)  (sizeof(TString) + ((l) + 1) * sizeof(char))
+/*
+** Size of a TString: Size of the header plus space for the string
+** itself (including final '\0').
+*/
+#define sizelstring(l)  (offsetof(TString, contents) + ((l) + 1) * sizeof(char))
 
 #define luaS_newliteral(L, s)   (luaS_newlstr(L, "" s, \
                                  (sizeof(s)/sizeof(char))-1))