diff --git a/src/testdir/dumps/Test_ambiwidth_hl_dump_1.dump b/src/testdir/dumps/Test_ambiwidth_hl_dump_1.dump
new file mode 100644
index 0000000..383a6f4
--- /dev/null
+++ b/src/testdir/dumps/Test_ambiwidth_hl_dump_1.dump
@@ -0,0 +1,6 @@
+>℃+8&#ffffff0@49
+@10|$+8#4040ff13&| +8#0000000&@38
+|℃+0&&@49
+@10|$+0#4040ff13&| +0#0000000&@38
+|~+0#4040ff13&| @48
+| +0#0000000&@31|1|,|1| @10|A|l@1| 
diff --git a/src/testdir/dumps/Test_ambiwidth_hl_dump_2.dump b/src/testdir/dumps/Test_ambiwidth_hl_dump_2.dump
new file mode 100644
index 0000000..81aeb7b
--- /dev/null
+++ b/src/testdir/dumps/Test_ambiwidth_hl_dump_2.dump
@@ -0,0 +1,6 @@
+>℃+8&#ffffff0| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| 
+|℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| 
+|℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |$+8#4040ff13&| +8#0000000&@28
+|℃+0&&| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| 
+|℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| |℃| @1|@+0#4040ff13&@2
+| +0#0000000&@31|1|,|1| @10|T|o|p| 
diff --git a/src/testdir/test_regexp_utf8.vim b/src/testdir/test_regexp_utf8.vim
index 6669dee..bc70544 100644
--- a/src/testdir/test_regexp_utf8.vim
+++ b/src/testdir/test_regexp_utf8.vim
@@ -342,7 +342,7 @@
 endfunc
 
 " check that 'ambiwidth' does not change the meaning of \p
-func Test_ambiwidth()
+func Test_regexp_ambiwidth()
   set regexpengine=1 ambiwidth=single
   call assert_equal(0, match("\u00EC", '\p'))
   set regexpengine=1 ambiwidth=double
diff --git a/src/testdir/test_utf8.vim b/src/testdir/test_utf8.vim
index deb96ea..df0abd3 100644
--- a/src/testdir/test_utf8.vim
+++ b/src/testdir/test_utf8.vim
@@ -62,6 +62,9 @@
   call assert_equal('"Test3 N', getreg(':'))
 
   call garbagecollect(1)
+  delcommand Test1
+  delcommand Test2
+  delcommand Test3
 endfunc
 
 " Yank one 3 byte character and check the mark columns.
@@ -297,6 +300,40 @@
   call StopVimInTerminal(buf)
 endfunc
 
+" For some reason this test causes Test_customlist_completion() to fail on CI,
+" so run it as the last test.
+func Test_zz_ambiwidth_hl_dump()
+  CheckRunVimInTerminal
+
+  let lines =<< trim END
+      call setline(1, [repeat("\u2103", 60), repeat("\u2103", 60)])
+      set ambiwidth=single cursorline list display=lastline
+  END
+  call writefile(lines, 'XAmbiwidthHl', 'D')
+  let buf = RunVimInTerminal('-S XAmbiwidthHl', {'rows': 6, 'cols': 50})
+  call VerifyScreenDump(buf, 'Test_ambiwidth_hl_dump_1', {})
+
+  call term_sendkeys(buf, ":set ambiwidth=double\<CR>")
+  call term_sendkeys(buf, ":echo\<CR>")
+  call VerifyScreenDump(buf, 'Test_ambiwidth_hl_dump_2', {})
+
+  call term_sendkeys(buf, ":set ambiwidth=single\<CR>")
+  call term_sendkeys(buf, ":echo\<CR>")
+  call VerifyScreenDump(buf, 'Test_ambiwidth_hl_dump_1', {})
+
+  if 0 " Enable after #14539 is fixed
+  call term_sendkeys(buf, ":call setcellwidths([[0x2103, 0x2103, 2]])\<CR>")
+  call term_sendkeys(buf, ":echo\<CR>")
+  call VerifyScreenDump(buf, 'Test_ambiwidth_hl_dump_2', {})
+
+  call term_sendkeys(buf, ":call setcellwidths([[0x2103, 0x2103, 1]])\<CR>")
+  call term_sendkeys(buf, ":echo\<CR>")
+  call VerifyScreenDump(buf, 'Test_ambiwidth_hl_dump_1', {})
+  endif
+
+  call StopVimInTerminal(buf)
+endfunc
+
 func Test_print_overlong()
   " Text with more composing characters than MB_MAXBYTES.
   new
diff --git a/src/version.c b/src/version.c
index fc10c7c..7a942c2 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    334,
+/**/
     333,
 /**/
     332,