diff --git a/tests/browser/test_webelem.py b/tests/browser/test_webelem.py
index d88bbc6aa..72ab7274f 100644
--- a/tests/browser/test_webelem.py
+++ b/tests/browser/test_webelem.py
@@ -25,10 +25,12 @@ from unittest import mock
 import collections.abc
 import operator
 import itertools
+import binascii
+import os.path
 
 import hypothesis
 import hypothesis.strategies
-from PyQt5.QtCore import QRect, QPoint
+from PyQt5.QtCore import PYQT_VERSION, QRect, QPoint
 from PyQt5.QtWebKit import QWebElement
 import pytest
 
@@ -525,21 +527,63 @@ class TestJavascriptEscape:
         """Test javascript escaping with some expected outcomes."""
         assert webelem.javascript_escape(before) == after
 
-    def _test_escape(self, text, webframe):
+    def _test_escape(self, text, qtbot, webframe):
         """Helper function for test_real_escape*."""
+        try:
+            self._test_escape_simple(text, webframe)
+        except AssertionError:
+            # Try another method if the simple method failed.
+            #
+            # See _test_escape_hexlified documentation on why this is
+            # necessary.
+            self._test_escape_hexlified(text, qtbot, webframe)
+
+    def _test_escape_hexlified(self, text, qtbot, webframe):
+        """Test conversion by hexlifying in javascript.
+
+        Since the conversion of QStrings to Python strings is broken in some
+        older PyQt versions in some corner cases, we load a HTML file which
+        generates an MD5 of the escaped text and use that for comparisons.
+        """
         escaped = webelem.javascript_escape(text)
-        webframe.evaluateJavaScript('window.foo = "{}";'.format(escaped))
-        assert webframe.evaluateJavaScript('window.foo') == text
+        path = os.path.join(os.path.dirname(__file__),
+                            'test_webelem_jsescape.html')
+        with open(path, encoding='utf-8') as f:
+            html_source = f.read().replace('%INPUT%', escaped)
+
+        with qtbot.waitSignal(webframe.loadFinished, raising=True):
+            webframe.setHtml(html_source)
+
+        result = webframe.evaluateJavaScript('window.qute_test_result')
+        assert result is not None
+        assert '|' in result
+        result_md5, result_text = result.split('|', maxsplit=1)
+        text_md5 = binascii.hexlify(text.encode('utf-8')).decode('ascii')
+        assert result_md5 == text_md5, result_text
+
+    def _test_escape_simple(self, text, webframe):
+        """Test conversion by using evaluateJavaScript."""
+        escaped = webelem.javascript_escape(text)
+        result = webframe.evaluateJavaScript('"{}";'.format(escaped))
+        assert result == text
 
     @pytest.mark.parametrize('text', TESTS)
-    def test_real_escape(self, webframe, text):
+    def test_real_escape(self, webframe, qtbot, text):
         """Test javascript escaping with a real QWebPage."""
-        self._test_escape(text, webframe)
+        self._test_escape(text, qtbot, webframe)
 
     @hypothesis.given(hypothesis.strategies.text())
-    def test_real_escape_hypothesis(self, webframe, text):
+    def test_real_escape_hypothesis(self, webframe, qtbot, text):
         """Test javascript escaping with a real QWebPage and hypothesis."""
-        self._test_escape(text, webframe)
+        # We can't simply use self._test_escape because of this:
+        # https://github.com/pytest-dev/pytest-qt/issues/69
+
+        # self._test_escape(text, qtbot, webframe)
+        try:
+            self._test_escape_simple(text, webframe)
+        except AssertionError:
+            if PYQT_VERSION >= 0x050300:
+                self._test_escape_hexlified(text, qtbot, webframe)
 
 
 class TestGetChildFrames:
diff --git a/tests/browser/test_webelem_jsescape.html b/tests/browser/test_webelem_jsescape.html
new file mode 100644
index 000000000..937499258
--- /dev/null
+++ b/tests/browser/test_webelem_jsescape.html
@@ -0,0 +1,68 @@
+<!--
+Helper file for test_javascript_escape() in test_webelem.py.
+
+Since the conversion from QStrings to Python strings is broken in some corner
+cases in PyQt < 5.4 we hexlify the string we got in javascript here and test
+that in the test.
+-->
+
+<html>
+<head>
+<script type="text/javascript">
+//<![CDATA[
+
+/*
+ * hexlify() and str2rstr_utf8() are based on:
+ *
+ * JavaScript MD5 1.0.1
+ * https://github.com/blueimp/JavaScript-MD5
+ *
+ * Copyright 2011, Sebastian Tschan
+ * https://blueimp.net
+ *
+ * Licensed under the MIT license:
+ * http://www.opensource.org/licenses/MIT
+ *
+ * Based on
+ * A JavaScript implementation of the RSA Data Security, Inc. MD5 Message
+ * Digest Algorithm, as defined in RFC 1321.
+ * Version 2.2 Copyright (C) Paul Johnston 1999 - 2009
+ * Other contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet
+ * Distributed under the BSD License
+ * See http://pajhome.org.uk/crypt/md5 for more info.
+ */
+
+'use strict';
+
+function hexlify(input) {
+    var hex_tab = '0123456789abcdef';
+    var output = '';
+    var x;
+    var i;
+
+    for (i = 0; i < input.length; i += 1) {
+        x = input.charCodeAt(i);
+        output += hex_tab.charAt((x >>> 4) & 0x0F) + hex_tab.charAt(x & 0x0F);
+    }
+
+    return output;
+}
+
+function encode_utf8(input) {
+    return unescape(encodeURIComponent(input));
+}
+
+function set_text() {
+    var elems = document.getElementsByTagName("p");
+    var hexlified = hexlify(encode_utf8("%INPUT%"));
+    var result = hexlified + "|" + "%INPUT%";
+    elems[0].innerHTML = result
+    window.qute_test_result = result;
+}
+
+//]]>
+</script>
+</head>
+<body onload="set_text()">
+<p>set_text() not called...</p>
+</html>