diff --git a/src/finder.h b/src/finder.h
index 6ba3e17..a421498 100644
--- a/src/finder.h
+++ b/src/finder.h
@@ -725,7 +725,7 @@ public:
 	}
 
 
-	Finder<ModelClass> & raw(pt::TextStream & sql, bool add_spaces = true)
+	Finder<ModelClass> & raw(const pt::TextStream & sql, bool add_spaces = true)
 	{
 		if( out_stream )
 		{