diff --git a/src/libexpr/attr-set.cc b/src/libexpr/attr-set.cc
index 0785897d2..b1d61a285 100644
--- a/src/libexpr/attr-set.cc
+++ b/src/libexpr/attr-set.cc
@@ -43,6 +43,12 @@ Value * EvalState::allocAttr(Value & vAttrs, const Symbol & name)
 }
 
 
+Value * EvalState::allocAttr(Value & vAttrs, const std::string & name)
+{
+    return allocAttr(vAttrs, symbols.create(name));
+}
+
+
 void Bindings::sort()
 {
     std::sort(begin(), end());
diff --git a/src/libexpr/eval.hh b/src/libexpr/eval.hh
index d0f298e16..60cf0f87f 100644
--- a/src/libexpr/eval.hh
+++ b/src/libexpr/eval.hh
@@ -264,6 +264,7 @@ public:
     Env & allocEnv(size_t size);
 
     Value * allocAttr(Value & vAttrs, const Symbol & name);
+    Value * allocAttr(Value & vAttrs, const std::string & name);
 
     Bindings * allocBindings(size_t capacity);