diff --git a/src/map.c b/src/map.c
index 186550a..ad2e831 100644
--- a/src/map.c
+++ b/src/map.c
@@ -2325,8 +2325,7 @@
     int		mode;
     int		abbr = FALSE;
     int		get_dict = FALSE;
-    mapblock_T	*mp;
-    mapblock_T	*mp_simplified = NULL;
+    mapblock_T	*mp = NULL;
     int		buffer_local;
     int		flags = REPTERM_FROM_PART | REPTERM_DO_LT;
 
@@ -2362,8 +2361,6 @@
     {
 	// When the lhs is being simplified the not-simplified keys are
 	// preferred for printing, like in do_map().
-	// The "rhs" and "buffer_local" values are not expected to change.
-	mp_simplified = mp;
 	(void)replace_termcodes(keys, &alt_keys_buf,
 					flags | REPTERM_NO_SIMPLIFY, NULL);
 	rhs = check_map(alt_keys_buf, mode, exact, FALSE, abbr, &mp,
@@ -2384,7 +2381,7 @@
     }
     else if (rettv_dict_alloc(rettv) != FAIL && rhs != NULL)
 	mapblock2dict(mp, rettv->vval.v_dict,
-		    did_simplify ? mp_simplified->m_keys : NULL, buffer_local);
+			  did_simplify ? keys_simplified : NULL, buffer_local);
 
     vim_free(keys_buf);
     vim_free(alt_keys_buf);
diff --git a/src/testdir/test_map_functions.vim b/src/testdir/test_map_functions.vim
index 8b2f6a8..66f3479 100644
--- a/src/testdir/test_map_functions.vim
+++ b/src/testdir/test_map_functions.vim
@@ -74,6 +74,12 @@
   call assert_equal(['{', 'w', 's'], [d.lhs, d.rhs, d.mode])
   sunmap {
 
+  map <C-I> foo
+  unmap <Tab>
+  " This used to cause a segfault
+  call maparg('<C-I>', '', 0, 1)
+  unmap <C-I>
+
   map abc <Nop>
   call assert_equal("<Nop>", maparg('abc'))
   unmap abc
@@ -82,6 +88,7 @@
   let d = maparg('esc', 'i', 1, 1)
   call assert_equal(['esc', "\<C-V>\<C-V>\<Esc>", '!'], [d.lhs, d.rhs, d.mode])
   abclear
+  unlet d
 endfunc
 
 def Test_vim9_maparg()
diff --git a/src/version.c b/src/version.c
index 1c799d8..ba27532 100644
--- a/src/version.c
+++ b/src/version.c
@@ -747,6 +747,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4831,
+/**/
     4830,
 /**/
     4829,