check for unicode first before encoding

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/sqlalchemy/engine/base.py b/lib/sqlalchemy/engine/base.py
index 1a13fdeeb..f426d93a6 100644
--- a/lib/sqlalchemy/engine/base.py
+++ b/lib/sqlalchemy/engine/base.py
@@ -1825,7 +1825,7 @@ class DefaultRunner(schema.SchemaVisitor):
         """execute a string statement, using the raw cursor,
         and return a scalar result."""
         conn = self.context._connection
-        if not self.dialect.supports_unicode_statements:
+        if isinstance(stmt, unicode) and not self.dialect.supports_unicode_statements:
             stmt = stmt.encode(self.dialect.encoding)
         conn._cursor_execute(self.context.cursor, stmt, params)
         return self.context.cursor.fetchone()[0]