diff --git a/src/libcmd/repl.cc b/src/libcmd/repl.cc
index 4ecbf51b5..57463bd79 100644
--- a/src/libcmd/repl.cc
+++ b/src/libcmd/repl.cc
@@ -641,9 +641,9 @@ bool NixRepl::processLine(string line)
             isVarName(name = removeWhitespace(string(line, 0, p))))
         {
             Expr * e = parseString(string(line, p + 1));
-            Value *v = new Value(*state->allocValue());
-            v->mkThunk(env, e);
-            addVarToScope(state->symbols.create(name), *v);
+            Value & v(*state->allocValue());
+            v.mkThunk(env, e);
+            addVarToScope(state->symbols.create(name), v);
         } else {
             Value v;
             evalString(line, v);