diff --git a/src/shared/urls.js b/src/shared/urls.js
index 87b1a48..d6c31e6 100644
--- a/src/shared/urls.js
+++ b/src/shared/urls.js
@@ -3,23 +3,29 @@ const trimStart = (str) => {
   return str.replace(/^\s+/, '');
 };
 
+const SUPPORTED_PROTOCOLS = ['http:', 'https:', 'ftp:', 'mailto:'];
+
 const normalizeUrl = (keywords, searchSettings) => {
   try {
-    return new URL(keywords).href;
-  } catch (e) {
-    if (keywords.includes('.') && !keywords.includes(' ')) {
-      return 'http://' + keywords;
+    let u = new URL(keywords);
+    if (SUPPORTED_PROTOCOLS.includes(u.protocol.toLowerCase())) {
+      return u.href;
     }
-    let template = searchSettings.engines[searchSettings.default];
-    let query = keywords;
+  } catch (e) {
+    // fallthrough
+  }
+  if (keywords.includes('.') && !keywords.includes(' ')) {
+    return 'http://' + keywords;
+  }
+  let template = searchSettings.engines[searchSettings.default];
+  let query = keywords;
 
-    let first = trimStart(keywords).split(' ')[0];
-    if (Object.keys(searchSettings.engines).includes(first)) {
-      template = searchSettings.engines[first];
-      query = trimStart(trimStart(keywords).slice(first.length));
-    }
-    return template.replace('{}', encodeURIComponent(query));
+  let first = trimStart(keywords).split(' ')[0];
+  if (Object.keys(searchSettings.engines).includes(first)) {
+    template = searchSettings.engines[first];
+    query = trimStart(trimStart(keywords).slice(first.length));
   }
+  return template.replace('{}', encodeURIComponent(query));
 };
 
 export { normalizeUrl };
diff --git a/test/shared/urls.test.js b/test/shared/urls.test.js
index 5573766..5c5e1a9 100644
--- a/test/shared/urls.test.js
+++ b/test/shared/urls.test.js
@@ -11,6 +11,8 @@ describe("shared/commands/parsers", () => {
     };
 
     it('convertes search url', () => {
+      expect(parsers.normalizeUrl('google.com', config))
+        .to.equal('http://google.com');
       expect(parsers.normalizeUrl('google apple', config))
         .to.equal('https://google.com/search?q=apple');
       expect(parsers.normalizeUrl('yahoo apple', config))
@@ -25,6 +27,13 @@ describe("shared/commands/parsers", () => {
       expect(parsers.normalizeUrl('apple banana', config))
         .to.equal('https://google.com/search?q=apple%20banana');
     });
+
+    it('searches with a word containing a colon', () => {
+      expect(parsers.normalizeUrl('foo:', config))
+        .to.equal('https://google.com/search?q=foo%3A');
+      expect(parsers.normalizeUrl('std::vector', config))
+        .to.equal('https://google.com/search?q=std%3A%3Avector');
+    });
   });
 });