diff --git a/packages/docusaurus-theme-classic/src/theme/Icon/ExternalLink/index.tsx b/packages/docusaurus-theme-classic/src/theme/Icon/ExternalLink/index.tsx
index b899a1fee742..817f33224084 100644
--- a/packages/docusaurus-theme-classic/src/theme/Icon/ExternalLink/index.tsx
+++ b/packages/docusaurus-theme-classic/src/theme/Icon/ExternalLink/index.tsx
@@ -16,8 +16,8 @@ import styles from './styles.module.css';
 const svgSprite = '#theme-svg-external-link';
 
 export default function IconExternalLink({
-  width = 13.5,
-  height = 13.5,
+  width = '0.84375rem',
+  height = '0.84375rem',
 }: Props): ReactNode {
   return (
     <svg
diff --git a/packages/docusaurus-theme-classic/src/theme/NavbarItem/NavbarNavLink.tsx b/packages/docusaurus-theme-classic/src/theme/NavbarItem/NavbarNavLink.tsx
index 52e198d33b81..485c1e86c06a 100644
--- a/packages/docusaurus-theme-classic/src/theme/NavbarItem/NavbarNavLink.tsx
+++ b/packages/docusaurus-theme-classic/src/theme/NavbarItem/NavbarNavLink.tsx
@@ -40,7 +40,7 @@ export default function NavbarNavLink({
             {label}
             {isExternalLink && (
               <IconExternalLink
-                {...(isDropdownLink && {width: 12, height: 12})}
+                {...(isDropdownLink && {width: '0.75rem', height: '0.75rem'})}
               />
             )}
           </>