1 files changed, 5 insertions, 3 deletions

diff --git a/src/floatfns.c b/src/floatfns.c
index 1c3e40eefde..29e5c119a1f 100644
--- a/src/floatfns.c
+++ b/src/floatfns.c
@@ -987,16 +987,18 @@ int
 matherr (struct exception *x)
 {
   Lisp_Object args;
+  const char *name = x->name;
+
   if (! in_float)
     /* Not called from emacs-lisp float routines; do the default thing. */
     return 0;
   if (!strcmp (x->name, "pow"))
-    x->name = "expt";
+    name = "expt";
 
   args
-    = Fcons (build_string (x->name),
+    = Fcons (build_string (name),
              Fcons (make_float (x->arg1),
-                    ((!strcmp (x->name, "log") || !strcmp (x->name, "pow"))
+                    ((!strcmp (name, "log") || !strcmp (name, "pow"))
                      ? Fcons (make_float (x->arg2), Qnil)
                      : Qnil)));
   switch (x->type)