1 files changed, 13 insertions, 1 deletions

diff --git a/src/eval.c b/src/eval.c
index b531f790cc5..f3f14d60e1c 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -2217,7 +2217,19 @@ eval_sub (Lisp_Object form)
           goto retry;
         }
       if (EQ (funcar, Qmacro))
-        val = eval_sub (apply1 (Fcdr (fun), original_args));
+        {
+          ptrdiff_t count = SPECPDL_INDEX ();
+          extern Lisp_Object Qlexical_binding;
+          Lisp_Object exp;
+          /* Bind lexical-binding during expansion of the macro, so the
+             macro can know reliably if the code it outputs will be
+             interpreted using lexical-binding or not.  */
+          specbind (Qlexical_binding,
+                    NILP (Vinternal_interpreter_environment) ? Qnil : Qt);
+          exp = apply1 (Fcdr (fun), original_args);
+          unbind_to (count, Qnil);
+          val = eval_sub (exp);
+        }
       else if (EQ (funcar, Qlambda)
                || EQ (funcar, Qclosure))
         val = apply_lambda (fun, original_args);