1 files changed, 8 insertions, 1 deletions
diff --git a/lib/sqlalchemy/dialects/mysql/base.py b/lib/sqlalchemy/dialects/mysql/base.py
index 6883be5af..d70e9b606 100644
--- a/lib/sqlalchemy/dialects/mysql/base.py
+++ b/lib/sqlalchemy/dialects/mysql/base.py
@@ -1422,7 +1422,14 @@ class MySQLCompiler(compiler.SQLCompiler):
              self.process(join.onclause, **kwargs)))
 
     def for_update_clause(self, select):
-        if select.for_update == 'read':
+        # backwards compatibility
+        if isinstance(select.for_update, bool):
+            return ' FOR UPDATE'
+        elif isinstance(select.for_update, str):
+            if select.for_update == 'read':
+                return ' LOCK IN SHARE MODE'
+
+        if select.for_update.mode == 'read':
             return ' LOCK IN SHARE MODE'
         else:
             return super(MySQLCompiler, self).for_update_clause(select)