1 files changed, 1 insertions, 1 deletions

diff --git a/src/eval.c b/src/eval.c
index 850f3866145..7034f43ca5a 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -1451,7 +1451,7 @@ find_handler_clause (handlers, conditions, sig, data, debugger_value_ptr)
 
       if (wants_debugger (Vstack_trace_on_error, conditions))
         {
-#ifdef __STDC__
+#ifdef PROTOTYPES
           internal_with_output_to_temp_buffer ("*Backtrace*",
                                                (Lisp_Object (*) (Lisp_Object)) Fbacktrace,
                                                Qnil);