Define calloc as well.
diff --git a/expat/xmltok/xmldef.h b/expat/xmltok/xmldef.h
index e165742..e03b2de 100755
--- a/expat/xmltok/xmldef.h
+++ b/expat/xmltok/xmldef.h
@@ -5,6 +5,7 @@
 
 #include "nspr.h"
 #define malloc(x) PR_Calloc(1,(x))
+#define calloc(x, y) PR_Calloc((x),(y))
 #define free(x) PR_Free(x)
 #define int int32