diff --git a/src/mbyte.c b/src/mbyte.c
index 406d109..07446ca 100644
--- a/src/mbyte.c
+++ b/src/mbyte.c
@@ -5542,6 +5542,20 @@
     return retval;
 }
 
+/*
+ * Return 1 or 2 when "c" is in the cellwidth table.
+ * Return 0 if not.
+ */
+    int
+get_cellwidth(int c UNUSED)
+{
+#ifdef FEAT_EVAL
+    return cw_value(c);
+#else
+    return 0;
+#endif
+}
+
 #if defined(FEAT_EVAL) || defined(PROTO)
 
 /*
diff --git a/src/proto/mbyte.pro b/src/proto/mbyte.pro
index 7883b3b..c57c94c 100644
--- a/src/proto/mbyte.pro
+++ b/src/proto/mbyte.pro
@@ -85,6 +85,7 @@
 int convert_input_safe(char_u *ptr, int len, int maxlen, char_u **restp, int *restlenp);
 char_u *string_convert(vimconv_T *vcp, char_u *ptr, int *lenp);
 char_u *string_convert_ext(vimconv_T *vcp, char_u *ptr, int *lenp, int *unconvlenp);
+int get_cellwidth(int c);
 void f_setcellwidths(typval_T *argvars, typval_T *rettv);
 void f_getcellwidths(typval_T *argvars, typval_T *rettv);
 void f_charclass(typval_T *argvars, typval_T *rettv);
diff --git a/src/screen.c b/src/screen.c
index 71ddbca..a8b4559 100644
--- a/src/screen.c
+++ b/src/screen.c
@@ -1981,7 +1981,24 @@
     {
 	char_u	    buf[MB_MAXBYTES + 1];
 
-	if (utf_ambiguous_width(ScreenLinesUC[off]))
+	if (get_cellwidth(ScreenLinesUC[off]) > 1)
+	{
+	    // If the width is set to 2 with `setcellwidths`
+
+#ifdef FEAT_GUI
+	    if (!gui.in_use)
+	    {
+#endif
+		// Clear the two screen cells. If the character is actually
+		// single width it won't change the second cell.
+		out_str((char_u *)"  ");
+		term_windgoto(row, col);
+		screen_cur_col = 9999;
+#ifdef FEAT_GUI
+	    }
+#endif
+	}
+	else if (utf_ambiguous_width(ScreenLinesUC[off]))
 	{
 	    if (*p_ambw == 'd'
 #ifdef FEAT_GUI
diff --git a/src/testdir/dumps/Test_setcellwidths_with_non_ambiwidth_character_dump_1.dump b/src/testdir/dumps/Test_setcellwidths_with_non_ambiwidth_character_dump_1.dump
new file mode 100644
index 0000000..73f4418
--- /dev/null
+++ b/src/testdir/dumps/Test_setcellwidths_with_non_ambiwidth_character_dump_1.dump
@@ -0,0 +1,6 @@
+>➜+0&#ffffff0@49
+@10| @39
+|➜@49
+@10| @39
+|~+0#4040ff13&| @48
+| +0#0000000&@31|1|,|1| @10|A|l@1| 
diff --git a/src/testdir/dumps/Test_setcellwidths_with_non_ambiwidth_character_dump_2.dump b/src/testdir/dumps/Test_setcellwidths_with_non_ambiwidth_character_dump_2.dump
new file mode 100644
index 0000000..2b575f6
--- /dev/null
+++ b/src/testdir/dumps/Test_setcellwidths_with_non_ambiwidth_character_dump_2.dump
@@ -0,0 +1,6 @@
+>➜+0&#ffffff0| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| 
+|➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| 
+|➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| @30
+|➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| |➜| 
+|@+0#4040ff13&@2| @46
+| +0#0000000&@31|1|,|1| @10|T|o|p| 
diff --git a/src/testdir/test_utf8.vim b/src/testdir/test_utf8.vim
index df0abd3..3fd83cf 100644
--- a/src/testdir/test_utf8.vim
+++ b/src/testdir/test_utf8.vim
@@ -300,6 +300,28 @@
   call StopVimInTerminal(buf)
 endfunc
 
+" When `setcellwidth` is used on characters that are not targets of `ambiwidth`.
+func Test_setcellwidths_with_non_ambiwidth_character_dump()
+  CheckRunVimInTerminal
+
+  let lines =<< trim END
+      call setline(1, [repeat("\u279c", 60), repeat("\u279c", 60)])
+      set ambiwidth=single
+  END
+  call writefile(lines, 'XCellwidthsWithNonAmbiwidthCharacter', 'D')
+  let buf = RunVimInTerminal('-S XCellwidthsWithNonAmbiwidthCharacter', {'rows': 6, 'cols': 50})
+  call term_sendkeys(buf, ":call setcellwidths([[0x279c, 0x279c, 1]])\<CR>")
+  call term_sendkeys(buf, ":echo\<CR>")
+  call VerifyScreenDump(buf, 'Test_setcellwidths_with_non_ambiwidth_character_dump_1', {})
+
+  call term_sendkeys(buf, ":call setcellwidths([[0x279c, 0x279c, 2]])\<CR>")
+  call term_sendkeys(buf, ":echo\<CR>")
+  call VerifyScreenDump(buf, 'Test_setcellwidths_with_non_ambiwidth_character_dump_2', {})
+
+  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()
@@ -321,7 +343,6 @@
   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', {})
@@ -329,7 +350,6 @@
   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
diff --git a/src/version.c b/src/version.c
index 3c1eae6..d4f82ba 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    344,
+/**/
     343,
 /**/
     342,