diff --git a/config/src/terminal.rs b/config/src/terminal.rs
index dedf4c07edf..9d96c41f141 100644
--- a/config/src/terminal.rs
+++ b/config/src/terminal.rs
@@ -3,6 +3,7 @@
 use crate::{configuration, ConfigHandle, NewlineCanon};
 use std::sync::Mutex;
 use termwiz::cell::UnicodeVersion;
+use termwiz::cell::setcellwidths;
 use wezterm_term::color::ColorPalette;
 use wezterm_term::config::BidiMode;
 
@@ -105,7 +106,7 @@ impl wezterm_term::TerminalConfiguration for TermConfig {
         UnicodeVersion {
             version: config.unicode_version,
             ambiguous_are_wide: config.treat_east_asian_ambiguous_width_as_wide,
-            cellwidths: config.cellwidths.clone()
+            cellwidths: setcellwidths(config.cellwidths.clone()),
         }
     }
 
diff --git a/termwiz/src/cell.rs b/termwiz/src/cell.rs
index 08f124d7dbd..09d6bbc6fec 100644
--- a/termwiz/src/cell.rs
+++ b/termwiz/src/cell.rs
@@ -12,6 +12,7 @@ use std::hash::{Hash, Hasher};
 use std::mem;
 use std::sync::Arc;
 use wezterm_dynamic::{FromDynamic, ToDynamic};
+use std::collections::HashMap;
 
 #[cfg_attr(feature = "use_serde", derive(Serialize, Deserialize))]
 #[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)]
@@ -888,11 +889,25 @@ pub struct CellWidth {
     pub width: u8,
 }
 
+pub fn setcellwidths(cellwidths: Option<Vec<CellWidth>>) -> Option<HashMap<u32, u8>> {
+    if let Some(ref cellwidths) = cellwidths {
+        let mut map: HashMap<u32, u8> = HashMap::new();
+        for cellwidth in cellwidths {
+            for i in cellwidth.first..cellwidth.last+1 {
+                map.insert(i, cellwidth.width);
+            }
+        }
+        return Some(map);
+    } else {
+        return None;
+    }
+}
+
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub struct UnicodeVersion {
     pub version: u8,
     pub ambiguous_are_wide: bool,
-    pub cellwidths: Option<Vec<CellWidth>>,
+    pub cellwidths: Option<HashMap<u32, u8>>,
 }
 
 impl UnicodeVersion {
@@ -923,10 +938,8 @@ impl UnicodeVersion {
     #[inline]
     fn wcwidth(&self, c: char) -> usize {
         if let Some(ref cellwidths) = self.cellwidths {
-            for cellwidth in cellwidths {
-                if cellwidth.first <= c as u32 && c as u32 <= cellwidth.last {
-                    return cellwidth.width.into()
-                }
+            if let Some(width) = cellwidths.get(&(c as u32)) {
+                return (*width).into()
             }
         }
         self.width(WCWIDTH_TABLE.classify(c))
diff --git a/wezterm-gui/src/main.rs b/wezterm-gui/src/main.rs
index bbe24e2fa89..cdc0e6a2181 100644
--- a/wezterm-gui/src/main.rs
+++ b/wezterm-gui/src/main.rs
@@ -33,6 +33,7 @@ use wezterm_font::FontConfiguration;
 use wezterm_gui_subcommands::*;
 use wezterm_mux_server_impl::update_mux_domains;
 use wezterm_toast_notification::*;
+use termwiz::cell::setcellwidths;
 
 mod colorease;
 mod commands;
@@ -886,7 +887,7 @@ pub fn run_ls_fonts(config: config::ConfigHandle, cmd: &LsFontsCommand) -> anyho
     let unicode_version = UnicodeVersion {
         version: config.unicode_version,
         ambiguous_are_wide: config.treat_east_asian_ambiguous_width_as_wide,
-        cellwidths: config.cellwidths.clone(),
+        cellwidths: setcellwidths(config.cellwidths.clone()),
     };
 
     let text = match (&cmd.text, &cmd.codepoints) {