diff --git a/package.json b/package.json
index ee68f73c..53161867 100644
--- a/package.json
+++ b/package.json
@@ -26,7 +26,6 @@
   "dependencies": {
     "classnames": "^2.2.6",
     "escape-html": "^1.0.3",
-    "is-url": "^1.2.4",
     "lodash": "^4.17.15",
     "react-dropzone": "^11.0.1",
     "react-image-crop": "^8.4.2",
diff --git a/src/components/LinkInput.tsx b/src/components/LinkInput.tsx
index cd401d32..45bd45c2 100644
--- a/src/components/LinkInput.tsx
+++ b/src/components/LinkInput.tsx
@@ -1,6 +1,6 @@
 import React, { useRef, useState, useEffect } from 'react';
 import { Node, NodeEntry } from 'slate';
-import isUrl from 'is-url';
+import isUrl, { prependHttps } from '../utils/isUrl';
 import Modal from './Modal';
 
 interface LinkInputProps {
@@ -44,16 +44,10 @@ const LinkInput = (props: LinkInputProps): JSX.Element => {
   };
 
   const onChange = (e: React.ChangeEvent<HTMLInputElement>): void => {
-    const prependProtocol = (url: string): string => {
-      if (!/^(?:f|ht)tps?:\/\//.test(url)) {
-        url = 'https://' + url;
-      }
-      return url;
-    };
-    if (e.target.value.length <= url.length) {
-      setUrl(e.target.value);
+    if (e.target.value.length >= url.length) {
+      setUrl(prependHttps(e.target.value));
     } else {
-      setUrl(prependProtocol(e.currentTarget.value));
+      setUrl(e.target.value);
     }
   };
 
diff --git a/src/utils/isUrl.ts b/src/utils/isUrl.ts
new file mode 100644
index 00000000..9fdf38c4
--- /dev/null
+++ b/src/utils/isUrl.ts
@@ -0,0 +1,17 @@
+const protocolRe = /^(?:f|ht)tps?:\/\//;
+const hostnameRe = /([a-zA-Z]\.?)+\.([a-zA-Z]){2,}/;
+
+const urlRe = new RegExp(protocolRe.source + hostnameRe.source);
+const mailRe = new RegExp('^mailto:([a-zA-Z](\\.|\\+)?)+@' + hostnameRe.source);
+const onlyHostnameRe = new RegExp('^' + hostnameRe.source);
+
+const isUrl = (url: string): boolean => urlRe.test(url) || mailRe.test(url);
+
+export const prependHttps = (hostname: string): string => {
+  if (onlyHostnameRe.test(hostname)) {
+    return 'https://' + hostname;
+  }
+  return hostname;
+};
+
+export default isUrl;
diff --git a/yarn.lock b/yarn.lock
index 523d439c..43a33ebb 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3896,11 +3896,6 @@ is-symbol@^1.0.2:
   dependencies:
     has-symbols "^1.0.1"
 
-is-url@^1.2.4:
-  version "1.2.4"
-  resolved "https://registry.yarnpkg.com/is-url/-/is-url-1.2.4.tgz#04a4df46d28c4cff3d73d01ff06abeb318a1aa52"
-  integrity sha512-ITvGim8FhRiYe4IQ5uHSkj7pVaPDrCTkNd3yq3cV7iZAcJdHTUMPMEHcqSOy9xZ9qFenQCvi+2wjH9a1nXqHww==
-
 is-windows@^1.0.1, is-windows@^1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/is-windows/-/is-windows-1.0.2.tgz#d1850eb9791ecd18e6182ce12a30f396634bb19d"