diff --git a/src/libexpr/attr-path.cc b/src/libexpr/attr-path.cc
index b538377815..769acb6b8c 100644
--- a/src/libexpr/attr-path.cc
+++ b/src/libexpr/attr-path.cc
@@ -61,7 +61,7 @@ void findAlongAttrPath(EvalState & state, const string & attrPath,
             if (attrIndex >= v.list.length)
                 throw Error(format("list index %1% in selection path `%2%' is out of range") % attrIndex % curPath);
 
-            v = v.list.elems[attrIndex];
+            v = *v.list.elems[attrIndex];
         }
         
     }
diff --git a/src/libexpr/eval-test.cc b/src/libexpr/eval-test.cc
index a7786561e8..f7f91f503d 100644
--- a/src/libexpr/eval-test.cc
+++ b/src/libexpr/eval-test.cc
@@ -113,6 +113,7 @@ void run(Strings args)
     doTest(state, "with { x = 1; }; let inherit x; y = x; in y");
     doTest(state, "builtins.toXML 123");
     doTest(state, "builtins.toXML { a.b = \"x\" + \"y\"; c = [ 1 2 ] ++ [ 3 4 ]; }");
+    doTest(state, "builtins.attrNames { x = 1; y = 2; }");
 
     state.printStats();
 }
diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc
index d6e39f3654..69e7bd8b3c 100644
--- a/src/libexpr/eval.cc
+++ b/src/libexpr/eval.cc
@@ -50,7 +50,7 @@ std::ostream & operator << (std::ostream & str, Value & v)
     case tList:
         str << "[ ";
         for (unsigned int n = 0; n < v.list.length; ++n)
-            str << v.list.elems[n] << " ";
+            str << *v.list.elems[n] << " ";
         str << "]";
         break;
     case tThunk:
@@ -102,7 +102,7 @@ EvalState::EvalState()
     , baseEnvDispl(0)
     , staticBaseEnv(false, 0)
 {
-    nrEnvs = nrValuesInEnvs = nrValuesInLists = nrValues = 0;
+    nrEnvs = nrValuesInEnvs = nrValues = nrListElems = 0;
     nrEvaluated = recursionDepth = maxRecursionDepth = 0;
     deepestStack = (char *) -1;
 
@@ -251,6 +251,7 @@ Value * EvalState::lookupVar(Env * env, const VarRef & var)
 
 Value * EvalState::allocValues(unsigned int count)
 {
+    nrValues += count;
     return new Value[count]; // !!! check destructor
 }
 
@@ -268,8 +269,8 @@ void EvalState::mkList(Value & v, unsigned int length)
 {
     v.type = tList;
     v.list.length = length;
-    v.list.elems = allocValues(length);
-    nrValuesInLists += length;
+    v.list.elems = new Value *[length];
+    nrListElems += length;
 }
 
 
@@ -461,8 +462,11 @@ void ExprLet::eval(EvalState & state, Env & env, Value & v)
 void ExprList::eval(EvalState & state, Env & env, Value & v)
 {
     state.mkList(v, elems.size());
-    for (unsigned int n = 0; n < v.list.length; ++n)
-        mkThunk(v.list.elems[n], env, elems[n]);
+    Value * vs = state.allocValues(v.list.length);
+    for (unsigned int n = 0; n < v.list.length; ++n) {
+        v.list.elems[n] = &vs[n];
+        mkThunk(vs[n], env, elems[n]);
+    }
 }
 
 
@@ -543,7 +547,6 @@ void EvalState::callFunction(Value & fun, Value & arg, Value & v)
             primOp->primOp.fun(*this, vArgs, v);
         } else {
             Value * v2 = allocValues(2);
-            nrValues += 2;
             v2[0] = fun;
             v2[1] = arg;
             v.type = tPrimOpApp;
@@ -734,8 +737,6 @@ void ExprOpConcatLists::eval(EvalState & state, Env & env, Value & v)
     Value v2; state.eval(env, e2, v2);
     state.forceList(v2);
     state.mkList(v, v1.list.length + v2.list.length);
-    /* !!! This loses sharing with the original lists.  We could use a
-       tCopy node, but that would use more memory. */
     for (unsigned int n = 0; n < v1.list.length; ++n)
         v.list.elems[n] = v1.list.elems[n];
     for (unsigned int n = 0; n < v2.list.length; ++n)
@@ -810,7 +811,7 @@ void EvalState::strictForceValue(Value & v)
     
     else if (v.type == tList) {
         for (unsigned int n = 0; n < v.list.length; ++n)
-            strictForceValue(v.list.elems[n]);
+            strictForceValue(*v.list.elems[n]);
     }
 }
 
@@ -951,11 +952,11 @@ string EvalState::coerceToString(Value & v, PathSet & context,
         if (v.type == tList) {
             string result;
             for (unsigned int n = 0; n < v.list.length; ++n) {
-                result += coerceToString(v.list.elems[n],
+                result += coerceToString(*v.list.elems[n],
                     context, coerceMore, copyToStore);
                 if (n < v.list.length - 1
                     /* !!! not quite correct */
-                    && (v.list.elems[n].type != tList || v.list.elems[n].list.length != 0))
+                    && (v.list.elems[n]->type != tList || v.list.elems[n]->list.length != 0))
                     result += " ";
             }
             return result;
@@ -1009,14 +1010,14 @@ bool EvalState::eqValues(Value & v1, Value & v2)
         case tList:
             if (v2.type != tList || v1.list.length != v2.list.length) return false;
             for (unsigned int n = 0; n < v1.list.length; ++n)
-                if (!eqValues(v1.list.elems[n], v2.list.elems[n])) return false;
+                if (!eqValues(*v1.list.elems[n], *v2.list.elems[n])) return false;
             return true;
 
         case tAttrs: {
             if (v2.type != tAttrs || v1.attrs->size() != v2.attrs->size()) return false;
             Bindings::iterator i, j;
             for (i = v1.attrs->begin(), j = v2.attrs->begin(); i != v1.attrs->end(); ++i, ++j)
-                if (!eqValues(i->second, j->second)) return false;
+                if (i->first != j->first || !eqValues(i->second, j->second)) return false;
             return true;
         }
 
@@ -1046,8 +1047,8 @@ void EvalState::printStats()
         % nrEnvs % (nrEnvs * sizeof(Env)));
     printMsg(v, format("  values allocated in environments: %1% (%2% bytes)")
         % nrValuesInEnvs % (nrValuesInEnvs * sizeof(Value)));
-    printMsg(v, format("  values allocated in lists: %1% (%2% bytes)")
-        % nrValuesInLists % (nrValuesInLists * sizeof(Value)));
+    printMsg(v, format("  list elements: %1% (%2% bytes)")
+        % nrListElems % (nrListElems * sizeof(Value *)));
     printMsg(v, format("  misc. values allocated: %1% (%2% bytes) ")
         % nrValues % (nrValues * sizeof(Value)));
     printMsg(v, format("  symbols in symbol table: %1%") % symbols.size());
diff --git a/src/libexpr/eval.hh b/src/libexpr/eval.hh
index 313a1d9b8e..7252cae4b5 100644
--- a/src/libexpr/eval.hh
+++ b/src/libexpr/eval.hh
@@ -76,7 +76,7 @@ struct Value
         Bindings * attrs;
         struct {
             unsigned int length;
-            Value * elems;
+            Value * * elems;
         } list;
         struct {
             Env * env;
@@ -282,8 +282,8 @@ private:
     
     unsigned long nrEnvs;
     unsigned long nrValuesInEnvs;
-    unsigned long nrValuesInLists;
     unsigned long nrValues;
+    unsigned long nrListElems;
     unsigned long nrEvaluated;
     unsigned int recursionDepth;
     unsigned int maxRecursionDepth;
diff --git a/src/libexpr/get-drvs.cc b/src/libexpr/get-drvs.cc
index 3994701924..6964e3e3b7 100644
--- a/src/libexpr/get-drvs.cc
+++ b/src/libexpr/get-drvs.cc
@@ -48,7 +48,7 @@ MetaInfo DrvInfo::queryMetaInfo(EvalState & state) const
         } else if (i->second.type == tList) {
             value.type = MetaValue::tpStrings;
             for (unsigned int j = 0; j < i->second.list.length; ++j)
-                value.stringValues.push_back(state.forceStringNoCtx(i->second.list.elems[j]));
+                value.stringValues.push_back(state.forceStringNoCtx(*i->second.list.elems[j]));
         } else continue;
         meta[i->first] = value;
     }
@@ -206,8 +206,8 @@ static void getDerivations(EvalState & state, Value & vIn,
             startNest(nest, lvlDebug,
                 format("evaluating list element"));
             string pathPrefix2 = addToPath(pathPrefix, (format("%1%") % n).str());
-            if (getDerivation(state, v.list.elems[n], pathPrefix2, drvs, done))
-                getDerivations(state, v.list.elems[n], pathPrefix2, autoArgs, drvs, done);
+            if (getDerivation(state, *v.list.elems[n], pathPrefix2, drvs, done))
+                getDerivations(state, *v.list.elems[n], pathPrefix2, autoArgs, drvs, done);
         }
     }
 
diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index 0d7459feef..ae17506cee 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -311,7 +311,7 @@ static void prim_derivationStrict(EvalState & state, Value * * args, Value & v)
             if (key == "args") {
                 state.forceList(i->second);
                 for (unsigned int n = 0; n < i->second.list.length; ++n) {
-                    string s = state.coerceToString(i->second.list.elems[n], context, true);
+                    string s = state.coerceToString(*i->second.list.elems[n], context, true);
                     drv.args.push_back(s);
                 }
             }
@@ -651,14 +651,17 @@ static void prim_attrNames(EvalState & state, Value * * args, Value & v)
     state.forceAttrs(*args[0]);
 
     state.mkList(v, args[0]->attrs->size());
+    Value * vs = state.allocValues(v.list.length);
 
     StringSet names;
     foreach (Bindings::iterator, i, *args[0]->attrs)
         names.insert(i->first);
 
     unsigned int n = 0;
-    foreach (StringSet::iterator, i, names)
-        mkString(v.list.elems[n++], *i);
+    foreach (StringSet::iterator, i, names) {
+        v.list.elems[n] = &vs[n];
+        mkString(vs[n++], *i);
+    }
 }
 
 
@@ -701,8 +704,8 @@ static void prim_removeAttrs(EvalState & state, Value * * args, Value & v)
     state.cloneAttrs(*args[0], v);
 
     for (unsigned int i = 0; i < args[1]->list.length; ++i) {
-        state.forceStringNoCtx(args[1]->list.elems[i]);
-        v.attrs->erase(state.symbols.create(args[1]->list.elems[i].string.s));
+        state.forceStringNoCtx(*args[1]->list.elems[i]);
+        v.attrs->erase(state.symbols.create(args[1]->list.elems[i]->string.s));
     }
 }
 
@@ -718,7 +721,7 @@ static void prim_listToAttrs(EvalState & state, Value * * args, Value & v)
     state.mkAttrs(v);
 
     for (unsigned int i = 0; i < args[0]->list.length; ++i) {
-        Value & v2(args[0]->list.elems[i]);
+        Value & v2(*args[0]->list.elems[i]);
         state.forceAttrs(v2);
         
         Bindings::iterator j = v2.attrs->find(state.sName);
@@ -815,8 +818,8 @@ static void prim_head(EvalState & state, Value * * args, Value & v)
     state.forceList(*args[0]);
     if (args[0]->list.length == 0)
         throw Error("`head' called on an empty list");
-    state.forceValue(args[0]->list.elems[0]);
-    v = args[0]->list.elems[0];
+    state.forceValue(*args[0]->list.elems[0]);
+    v = *args[0]->list.elems[0];
 }
 
 
@@ -840,11 +843,13 @@ static void prim_map(EvalState & state, Value * * args, Value & v)
     state.forceList(*args[1]);
 
     state.mkList(v, args[1]->list.length);
+    Value * vs = state.allocValues(v.list.length);
 
     for (unsigned int n = 0; n < v.list.length; ++n) {
-        v.list.elems[n].type = tApp;
-        v.list.elems[n].app.left = args[0];
-        v.list.elems[n].app.right = &args[1]->list.elems[n];
+        v.list.elems[n] = &vs[n];
+        vs[n].type = tApp;
+        vs[n].app.left = args[0];
+        vs[n].app.right = args[1]->list.elems[n];
     }
 }
 
diff --git a/src/libexpr/value-to-xml.cc b/src/libexpr/value-to-xml.cc
index 0c8fc143c3..58e89925ce 100644
--- a/src/libexpr/value-to-xml.cc
+++ b/src/libexpr/value-to-xml.cc
@@ -97,7 +97,7 @@ static void printValueAsXML(EvalState & state, bool strict, Value & v,
         case tList: {
             XMLOpenElement _(doc, "list");
             for (unsigned int n = 0; n < v.list.length; ++n)
-                printValueAsXML(state, strict, v.list.elems[n], doc, context, drvsSeen);
+                printValueAsXML(state, strict, *v.list.elems[n], doc, context, drvsSeen);
             break;
         }