diff --git a/flask_sqlalchemy_caching/core.py b/flask_sqlalchemy_caching/core.py
index e86b2f7..f53a751 100644
--- a/flask_sqlalchemy_caching/core.py
+++ b/flask_sqlalchemy_caching/core.py
@@ -129,7 +129,7 @@ def key_from_query(self, qualifier=None):
         particular Query, then combining that with the bound parameter values.
         """
         stmt = self.with_labels().statement
-        key = str(stmt.compile(compile_kwargs={'literal_binds': True}))
+        key = stmt.compile(compile_kwargs={'literal_binds': True}).__str__()
         return md5(key.encode('utf8')).hexdigest()