diff --git a/src/lisp.h b/src/lisp.h
index ee50cc777c6..a5082146da7 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -5608,7 +5608,7 @@ extern void init_system_name (void);
       systems to detect stack exhaustion and enlarge the stack as
       needed; this thus risks hitting a segfault where none should
       have happened.  (This problem is real in deeply-recursive cases,
-      but these do happen in Emacs, e.g. in regexp search or during GC.)  */
+      e.g., in regexp search or during GC.)  */
 
 enum MAX_ALLOCA { MAX_ALLOCA = 16 * 1024 };
 
@@ -5697,32 +5697,23 @@ safe_free_unbind_to (specpdl_ref count, specpdl_ref sa_count, Lisp_Object val)
 # pragma GCC diagnostic ignored "-Wanalyzer-allocation-size"
 #endif
 
-/* Set BUF to point to an allocated array of NELT Lisp_Objects,
-   immediately followed by EXTRA spare bytes.  */
+/* Set BUF to point to an allocated array of NELT Lisp_Objects.  */
 
-#define SAFE_ALLOCA_LISP_EXTRA(buf, nelt, extra)	       \
+#define SAFE_ALLOCA_LISP(buf, nelt)			       \
   do {							       \
     ptrdiff_t alloca_nbytes;				       \
     if (ckd_mul (&alloca_nbytes, nelt, word_size)	       \
-	|| ckd_add (&alloca_nbytes, alloca_nbytes, extra)      \
 	|| SIZE_MAX < alloca_nbytes)			       \
       memory_full (SIZE_MAX);				       \
     else if (alloca_nbytes <= sa_avail)			       \
       (buf) = AVAIL_ALLOCA (alloca_nbytes);		       \
     else						       \
       {							       \
-	/* Although only the first nelt words need clearing,   \
-	   typically EXTRA is 0 or small so just use xzalloc;  \
-	   this is simpler and often faster.  */	       \
 	(buf) = xzalloc (alloca_nbytes);		       \
 	record_unwind_protect_array (buf, nelt);	       \
       }							       \
   } while (false)
 
-/* Set BUF to point to an allocated array of NELT Lisp_Objects.  */
-
-#define SAFE_ALLOCA_LISP(buf, nelt) SAFE_ALLOCA_LISP_EXTRA (buf, nelt, 0)
-
 
 /* If USE_STACK_LISP_OBJECTS, define macros and functions that
    allocate some Lisp objects on the C stack.  As the storage is not