diff --git a/include/MySQL_Thread.h b/include/MySQL_Thread.h
index cfb2eb2e5..982dcf1e0 100644
--- a/include/MySQL_Thread.h
+++ b/include/MySQL_Thread.h
@@ -21,7 +21,7 @@
 #define MYSQL_DEFAULT_TIME_ZONE	"SYSTEM"
 #define MYSQL_DEFAULT_ISOLATION_LEVEL	"READ COMMITTED"
 #define MYSQL_DEFAULT_TRANSACTION_READ	"WRITE"
-#define MYSQL_DEFAULT_TX_ISOLATION	"READ COMMITTED"
+#define MYSQL_DEFAULT_TX_ISOLATION	"READ-COMMITTED"
 #define MYSQL_DEFAULT_CHARACTER_SET_RESULTS	"NULL"
 #define MYSQL_DEFAULT_SESSION_TRACK_GTIDS	"OFF"
 #define MYSQL_DEFAULT_SQL_AUTO_IS_NULL	"OFF"