diff --git a/src/protocol/eval/store.rs b/src/protocol/eval/store.rs
index 3e8de99be086a6dbc2ca9c2f901e6dd359361570..de98d77e70a5314dc0f094dd8b0dff51bc257d53 100644
--- a/src/protocol/eval/store.rs
+++ b/src/protocol/eval/store.rs
@@ -179,6 +179,7 @@ impl Store {
 
         match value {
             Value::Message(_) => Value::Message(target_heap_pos),
+            Value::String(_) => Value::String(target_heap_pos),
             Value::Array(_) => Value::Array(target_heap_pos),
             Value::Union(tag, _) => Value::Union(tag, target_heap_pos),
             Value::Struct(_) => Value::Struct(target_heap_pos),