diff --git a/markdownify/__init__.py b/markdownify/__init__.py
index 28cdaf6..e3d6810 100644
--- a/markdownify/__init__.py
+++ b/markdownify/__init__.py
@@ -442,6 +442,9 @@ def convert_a(self, el, text, parent_tags):
         if not text:
             return ''
         href = el.get('href')
+        # Escape parentheses in URLs to prevent breaking markdown link syntax
+        if href:
+            href = href.replace('(', '%28').replace(')', '%29')
         title = el.get('title')
         # For the replacement see #29: text nodes underscores are escaped
         if (self.options['autolinks']
diff --git a/tests/test_conversions.py b/tests/test_conversions.py
index c95483c..5e02e7b 100644
--- a/tests/test_conversions.py
+++ b/tests/test_conversions.py
@@ -45,6 +45,14 @@ def test_a_in_code():
     assert md('<pre><a href="https://google.com">Google</a></pre>') == '\n\n```\nGoogle\n```\n\n'
 
 
+def test_a_parentheses_in_url():
+    html = ('<a href="http://en.wiktionary.org/wiki/)">close-paren on wiktionary</a>'
+            '<br/><a href="http://en.wiktionary.org/wiki/(">open-paren on wiktionary</a>')
+    expected = ('[close-paren on wiktionary](http://en.wiktionary.org/wiki/%29)  \n'
+                '[open-paren on wiktionary](http://en.wiktionary.org/wiki/%28)')
+    assert md(html) == expected
+
+
 def test_b():
     assert md('<b>Hello</b>') == '**Hello**'