diff --git a/ext/mbstring/mbstring.c b/ext/mbstring/mbstring.c
index d31cd5a9e8b..4811825e5ca 100644
--- a/ext/mbstring/mbstring.c
+++ b/ext/mbstring/mbstring.c
@@ -3927,7 +3927,7 @@ PHP_FUNCTION(mb_send_mail)
 					if (strcasecmp(param_name, "charset") == 0) {
 						enum mbfl_no_encoding _tran_cs = tran_cs;
 						
-						charset = php_strtok_r(NULL, "= ", &tmp);
+						charset = php_strtok_r(NULL, "= \"", &tmp);
 						if (charset != NULL) {
 							_tran_cs = mbfl_name2no_encoding(charset);
 						}