1 files changed, 2 insertions, 1 deletions
diff --git a/src/source.rs b/src/source.rs
index 1a8d08f..bc1dd40 100644
--- a/src/source.rs
+++ b/src/source.rs
@@ -1,9 +1,10 @@
 use std::error::Error;
+use std::borrow::Cow;
 
 use value::Value;
 
 pub trait Source {
-    fn get(&self, key: &str) -> Option<Value>;
+    fn get<'a>(&self, key: &str) -> Option<Cow<'a, Value>>;
 }
 
 pub trait SourceBuilder {