diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index 6af179e4e..29b8500e0 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -3344,7 +3344,7 @@ static void prim_mapAttrs(EvalState & state, const PosIdx pos, Value ** args, Va
         Value * vName = Value::toPtr(state.symbols[i.name]);
         Value * vFun2 = state.allocValue();
         vFun2->mkApp(args[0], vName);
-        attrs.alloc(i.name).mkApp(vFun2, i.value);
+        attrs.alloc(i.name, i.pos).mkApp(vFun2, i.value);
     }
 
     v.mkAttrs(attrs.alreadySorted());
diff --git a/tests/functional/lang/eval-okay-getattrpos-mapattrs.exp b/tests/functional/lang/eval-okay-getattrpos-mapattrs.exp
new file mode 100644
index 000000000..f6dd73af0
--- /dev/null
+++ b/tests/functional/lang/eval-okay-getattrpos-mapattrs.exp
@@ -0,0 +1 @@
+{ column = 5; file = "/pwd/lang/eval-okay-getattrpos-mapattrs.nix"; line = 3; }
diff --git a/tests/functional/lang/eval-okay-getattrpos-mapattrs.nix b/tests/functional/lang/eval-okay-getattrpos-mapattrs.nix
new file mode 100644
index 000000000..4c4b76b82
--- /dev/null
+++ b/tests/functional/lang/eval-okay-getattrpos-mapattrs.nix
@@ -0,0 +1,7 @@
+let
+  attrs = {
+    a = { };
+  };
+
+  mappedAttrs = builtins.mapAttrs (key: value: value) attrs;
+in builtins.unsafeGetAttrPos "a" mappedAttrs