diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc
index 810843995..494b8338f 100644
--- a/src/libexpr/eval.cc
+++ b/src/libexpr/eval.cc
@@ -554,6 +554,8 @@ EvalState::EvalState(
 
     static_assert(sizeof(Env) <= 16, "environment must be <= 16 bytes");
 
+    vEmptyList.mkList(0);
+
     /* Initialise the Nix expression search path. */
     if (!evalSettings.pureEval) {
         for (auto & i : _searchPath.elements)
@@ -1384,6 +1386,15 @@ void ExprList::eval(EvalState & state, Env & env, Value & v)
 }
 
 
+Value * ExprList::maybeThunk(EvalState & state, Env & env)
+{
+    if (elems.empty()) {
+        return &state.vEmptyList;
+    }
+    return Expr::maybeThunk(state, env);
+}
+
+
 void ExprVar::eval(EvalState & state, Env & env, Value & v)
 {
     Value * v2 = state.lookupVar(&env, *this, false);
diff --git a/src/libexpr/eval.hh b/src/libexpr/eval.hh
index da2d256db..bf85b50c8 100644
--- a/src/libexpr/eval.hh
+++ b/src/libexpr/eval.hh
@@ -305,6 +305,9 @@ public:
         return *errorBuilder;
     }
 
+    /* Empty list constant. */
+    Value vEmptyList;
+
 private:
 
     /* Cache for calls to addToStore(); maps source paths to the store
diff --git a/src/libexpr/nixexpr.hh b/src/libexpr/nixexpr.hh
index 1e57fec7a..55e930758 100644
--- a/src/libexpr/nixexpr.hh
+++ b/src/libexpr/nixexpr.hh
@@ -299,6 +299,7 @@ struct ExprList : Expr
     std::vector<Expr *> elems;
     ExprList() { };
     COMMON_METHODS
+    Value * maybeThunk(EvalState & state, Env & env) override;
 
     PosIdx getPos() const override
     {