diff --git a/modules/ui/fields/wikipedia.js b/modules/ui/fields/wikipedia.js
index 832881c77..30f313d2a 100644
--- a/modules/ui/fields/wikipedia.js
+++ b/modules/ui/fields/wikipedia.js
@@ -11,6 +11,8 @@ import { utilGetSetValue, utilNoAuto, utilRebind } from '../../util';
 
 
 export function uiFieldWikipedia(field, context) {
+  const scheme = 'https://';
+  const domain = 'wikipedia.org';
   const dispatch = d3_dispatch('change');
   const wikipedia = services.wikipedia;
   const wikidata = services.wikidata;
@@ -132,7 +134,7 @@ export function uiFieldWikipedia(field, context) {
     link = link.enter()
       .append('button')
       .attr('class', 'form-field-button wiki-link')
-      .attr('title', t('icons.view_on', { domain: 'wikipedia.org' }))
+      .attr('title', t('icons.view_on', { domain }))
       .call(svgIcon('#iD-icon-out-link'))
       .merge(link);
 
@@ -280,24 +282,13 @@ export function uiFieldWikipedia(field, context) {
       const nativeLangName = tagLangInfo[1];
       utilGetSetValue(_langInput, nativeLangName);
       utilGetSetValue(_titleInput, tagArticleTitle + (anchor ? ('#' + anchor) : ''));
-      if (anchor) {
-        try {
-          // Best-effort `anchorencode:` implementation
-          anchor = encodeURIComponent(anchor.replace(/ /g, '_')).replace(/%/g, '.');
-        } catch (e) {
-          anchor = anchor.replace(/ /g, '_');
-        }
-      }
-      _wikiURL = 'https://' + tagLang + '.wikipedia.org/wiki/' +
-        tagArticleTitle.replace(/ /g, '_') + (anchor ? ('#' + anchor) : '');
-
-    // unrecognized value format
+      _wikiURL = `${scheme}${tagLang}.${domain}/wiki/${wiki.encodePath(tagArticleTitle, anchor)}`;
     } else {
       utilGetSetValue(_titleInput, value);
       if (value && value !== '') {
         utilGetSetValue(_langInput, '');
         const defaultLangInfo = defaultLanguageInfo();
-        _wikiURL = `https://${defaultLangInfo[2]}.wikipedia.org/w/index.php?fulltext=1&search=${value}`;
+        _wikiURL = `${scheme}${defaultLangInfo[2]}.${domain}/w/index.php?fulltext=1&search=${value}`;
       } else {
         const shownOrDefaultLangInfo = language(true /* skipEnglishFallback */);
         utilGetSetValue(_langInput, shownOrDefaultLangInfo[1]);
@@ -306,6 +297,18 @@ export function uiFieldWikipedia(field, context) {
     }
   }
 
+  wiki.encodePath = (tagArticleTitle, anchor) => {
+    const underscoredTitle = tagArticleTitle.replace(/ /g, '_');
+    const uriEncodedUnderscoredTitle = encodeURIComponent(underscoredTitle);
+    const uriEncodedAnchorFragment = wiki.encodeURIAnchorFragment(anchor);
+    return `${uriEncodedUnderscoredTitle}${uriEncodedAnchorFragment}`;
+  };
+
+  wiki.encodeURIAnchorFragment = (anchor) => {
+    if (!anchor) return '';
+    const underscoredAnchor = anchor.replace(/ /g, '_');
+    return '#' + encodeURIComponent(underscoredAnchor);
+  };
 
   wiki.entityIDs = (val) => {
     if (!arguments.length) return _entityIDs;
diff --git a/test/spec/ui/fields/wikipedia.js b/test/spec/ui/fields/wikipedia.js
index 6a6d4a122..dc31d78f9 100644
--- a/test/spec/ui/fields/wikipedia.js
+++ b/test/spec/ui/fields/wikipedia.js
@@ -113,6 +113,48 @@ describe('iD.uiFieldWikipedia', function() {
         }, 20);
     });
 
+    describe('encodePath', function() {
+        it('returns an encoded URI component that contains the title with spaces replaced by underscores', function(done) {
+            var wikipedia = iD.uiFieldWikipedia(field, context).entityIDs([entity.id]);
+            expect(wikipedia.encodePath('? (film)', undefined)).to.equal('%3F_(film)');
+            done();
+        });
+
+        it('returns an encoded URI component that includes an anchor fragment', function(done) {
+            var wikipedia = iD.uiFieldWikipedia(field, context).entityIDs([entity.id]);
+            // this can be tested manually by entering '? (film)#Themes and style in the search box before focusing out'
+            expect(wikipedia.encodePath('? (film)', 'Themes and style')).to.equal('%3F_(film)#Themes_and_style');
+            done();
+        });
+    });
+
+    describe('encodeURIAnchorFragment', function() {
+        it('returns an encoded URI anchor fragment', function(done) {
+            var wikipedia = iD.uiFieldWikipedia(field, context).entityIDs([entity.id]);
+            // this can be similarily tested by entering 'Section#Arts, entertainment and media' in the search box before focusing out'
+            expect(wikipedia.encodeURIAnchorFragment('Theme?')).to.equal('#Theme%3F');
+            done();
+        });
+
+        it('replaces all whitespace characters with underscore', function(done) {
+            var wikipedia = iD.uiFieldWikipedia(field, context).entityIDs([entity.id]);
+            expect(wikipedia.encodeURIAnchorFragment('Themes And Styles')).to.equal('#Themes_And_Styles');
+            done();
+        });
+
+        it('encodes % characters, does not replace them with a dot', function(done) {
+            var wikipedia = iD.uiFieldWikipedia(field, context).entityIDs([entity.id]);
+            expect(wikipedia.encodeURIAnchorFragment('Is%this_100% correct')).to.equal('#Is%25this_100%25_correct');
+            done();
+        });
+
+        it('encodes characters that are URI encoded characters', function (done) {
+            var wikipedia = iD.uiFieldWikipedia(field, context).entityIDs([entity.id]);
+            expect(wikipedia.encodeURIAnchorFragment('Section %20%25')).to.equal('#Section_%2520%2525');
+            done();
+        });
+    });
+
     // note - currently skipping the tests that use `options` to delay responses
     it('preserves existing language', function(done) {
         var wikipedia1 = iD.uiFieldWikipedia(field, context);