diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc
index 92516db3b..7346a7651 100644
--- a/src/libexpr/eval.cc
+++ b/src/libexpr/eval.cc
@@ -126,9 +126,9 @@ std::string showType(const Value & v)
     #pragma GCC diagnostic push
     #pragma GCC diagnostic ignored "-Wswitch-enum"
     switch (v.internalType) {
-        case tString: return v.payload.string.context ? "a string with context" : "a string";
+        case tString: return v.context() ? "a string with context" : "a string";
         case tPrimOp:
-            return fmt("the built-in function '%s'", std::string(v.payload.primOp->name));
+            return fmt("the built-in function '%s'", std::string(v.primOp()->name));
         case tPrimOpApp:
             return fmt("the partially applied built-in function '%s'", v.primOpAppPrimOp()->name);
         case tExternal: return v.external()->showType();
@@ -2297,8 +2297,8 @@ std::string_view EvalState::forceString(Value & v, const PosIdx pos, std::string
 
 void copyContext(const Value & v, NixStringContext & context, const ExperimentalFeatureSettings & xpSettings)
 {
-    if (v.payload.string.context)
-        for (const char * * p = v.payload.string.context; *p; ++p)
+    if (v.context())
+        for (const char * * p = v.context(); *p; ++p)
             context.insert(NixStringContextElem::parse(*p, xpSettings));
 }
 
diff --git a/src/libexpr/include/nix/expr/symbol-table.hh b/src/libexpr/include/nix/expr/symbol-table.hh
index 1bf5b5543..20a05a09d 100644
--- a/src/libexpr/include/nix/expr/symbol-table.hh
+++ b/src/libexpr/include/nix/expr/symbol-table.hh
@@ -29,7 +29,7 @@ class SymbolValue : protected Value
 public:
     operator std::string_view() const noexcept
     {
-        return {payload.string.c_str, size_};
+        return {c_str(), size_};
     }
 };
 
@@ -122,7 +122,7 @@ public:
     [[gnu::always_inline]]
     const char * c_str() const noexcept
     {
-        return s->payload.string.c_str;
+        return s->c_str();
     }
 
     [[gnu::always_inline]]