diff --git a/src/libexpr/include/nix/expr/nixexpr.hh b/src/libexpr/include/nix/expr/nixexpr.hh
index 747a8e4b2..2af6039cd 100644
--- a/src/libexpr/include/nix/expr/nixexpr.hh
+++ b/src/libexpr/include/nix/expr/nixexpr.hh
@@ -212,14 +212,16 @@ struct ExprString : Expr
 struct ExprPath : Expr
 {
     ref<SourceAccessor> accessor;
-    std::string s;
     Value v;
 
-    ExprPath(ref<SourceAccessor> accessor, std::string s)
+    ExprPath(std::pmr::polymorphic_allocator<char> & alloc, ref<SourceAccessor> accessor, std::string_view sv)
         : accessor(accessor)
-        , s(std::move(s))
     {
-        v.mkPath(&*accessor, this->s.c_str());
+        auto len = sv.length();
+        char * s = alloc.allocate(len + 1);
+        sv.copy(s, len);
+        s[len] = '\0';
+        v.mkPath(&*accessor, s);
     }
 
     Value * maybeThunk(EvalState & state, Env & env) override;
diff --git a/src/libexpr/nixexpr.cc b/src/libexpr/nixexpr.cc
index a2980af6b..014b85f20 100644
--- a/src/libexpr/nixexpr.cc
+++ b/src/libexpr/nixexpr.cc
@@ -45,7 +45,7 @@ void ExprString::show(const SymbolTable & symbols, std::ostream & str) const
 
 void ExprPath::show(const SymbolTable & symbols, std::ostream & str) const
 {
-    str << s;
+    str << v.pathStr();
 }
 
 void ExprVar::show(const SymbolTable & symbols, std::ostream & str) const
diff --git a/src/libexpr/parser.y b/src/libexpr/parser.y
index 7dabd6b56..bc1eb056e 100644
--- a/src/libexpr/parser.y
+++ b/src/libexpr/parser.y
@@ -392,8 +392,8 @@ path_start
            root filesystem accessor, rather than the accessor of the
            current Nix expression. */
         literal.front() == '/'
-        ? new ExprPath(state->rootFS, std::move(path))
-        : new ExprPath(state->basePath.accessor, std::move(path));
+        ? new ExprPath(state->alloc, state->rootFS, path)
+        : new ExprPath(state->alloc, state->basePath.accessor, path);
   }
   | HPATH {
     if (state->settings.pureEval) {
@@ -403,7 +403,7 @@ path_start
         );
     }
     Path path(getHome() + std::string($1.p + 1, $1.l - 1));
-    $$ = new ExprPath(ref<SourceAccessor>(state->rootFS), std::move(path));
+    $$ = new ExprPath(state->alloc, ref<SourceAccessor>(state->rootFS), path);
   }
   ;