diff --git a/docs/source/changelog.rst b/docs/source/changelog.rst
index c5ab996..8285f67 100644
--- a/docs/source/changelog.rst
+++ b/docs/source/changelog.rst
@@ -2,7 +2,18 @@
 Changelog
 ===============
 
-Version numbers follow `semantic versioning <https://semver.org>`__
+Version numbers follow `semantic versioning <https://semver.org>`__.
+
+
+not yet released
+----------------
+
+* **bug fix**
+
+  * ``espeak`` backend: words mismatch now works when using custom word
+    separators. See `issue #169
+    <https://github.com/bootphon/phonemizer/issues/169>`__.
+
 
 phonemizer-3.2.1
 ----------------
@@ -10,7 +21,7 @@ phonemizer-3.2.1
 * **bug fixes**
 
   * Fixed a bug when trying to restore punctuation on a multiline text.
-    See `issue #129 <https://github.com/bootphon/phonemizer/issues/129>`__
+    See `issue #129 <https://github.com/bootphon/phonemizer/issues/129>`__.
 
 
 phonemizer-3.2.0
@@ -19,14 +30,14 @@ phonemizer-3.2.0
 * **bug fixes**
 
   * Fixed a bug when trying to restore punctuation on very long text.
-    See `issue #108 <https://github.com/bootphon/phonemizer/issues/108>`__
+    See `issue #108 <https://github.com/bootphon/phonemizer/issues/108>`__.
 
 * **improvements**
 
   * Improved consistency with the handling of word separators when
     preserving punctuation, and when using a word separator that is
     not a literal space character. See
-    `issue #106 <https://github.com/bootphon/phonemizer/issues/106>`__
+    `issue #106 <https://github.com/bootphon/phonemizer/issues/106>`__.
 
 * **new features**
 
@@ -400,4 +411,4 @@ phonemizer-0.2
 
 -  First public release.
 
--  Support for festival backend, American English only.
\ No newline at end of file
+-  Support for festival backend, American English only.
diff --git a/phonemizer/backend/espeak/espeak.py b/phonemizer/backend/espeak/espeak.py
index 34e3faf..766af5b 100644
--- a/phonemizer/backend/espeak/espeak.py
+++ b/phonemizer/backend/espeak/espeak.py
@@ -150,7 +150,7 @@ def _phonemize_postprocess(self, phonemized, punctuation_marks, separator: Separ
         text = phonemized[0]
         switches = phonemized[1]
 
-        self._words_mismatch.count_phonemized(text)
+        self._words_mismatch.count_phonemized(text, separator)
         self._lang_switch.warning(switches)
 
         phonemized = super()._phonemize_postprocess(text, punctuation_marks, separator, strip)
diff --git a/phonemizer/backend/espeak/words_mismatch.py b/phonemizer/backend/espeak/words_mismatch.py
index bc5be0c..30f206b 100644
--- a/phonemizer/backend/espeak/words_mismatch.py
+++ b/phonemizer/backend/espeak/words_mismatch.py
@@ -19,7 +19,10 @@
 from logging import Logger
 from typing import List, Tuple
 
-from typing_extensions import TypeAlias, Literal
+from typing_extensions import TypeAlias, Literal, Union
+
+from phonemizer.separator import Separator
+
 
 WordMismatch: TypeAlias = Literal["warn", "ignore"]
 
@@ -58,10 +61,16 @@ def __init__(self, logger: Logger):
         self._count_phn = []
 
     @classmethod
-    def _count_words(cls, text: List[str]) -> List[int]:
+    def _count_words(
+            cls,
+            text: List[str],
+            wordsep: Union[str, re.Pattern] = _RE_SPACES) -> List[int]:
         """Return the number of words contained in each line of `text`"""
+        if not isinstance(wordsep, re.Pattern):
+            wordsep = re.escape(wordsep)
+
         return [
-            len([w for w in cls._RE_SPACES.split(line.strip()) if w])
+            len([w for w in re.split(wordsep, line.strip()) if w])
             for line in text]
 
     def _mismatched_lines(self) -> List[Tuple[int, int, int]]:
@@ -93,9 +102,9 @@ def count_text(self, text: List[str]):
         """Stores the number of words in each input line"""
         self._count_txt = self._count_words(text)
 
-    def count_phonemized(self, text: List[str]):
+    def count_phonemized(self, text: List[str], separator: Separator):
         """Stores the number of words in each output line"""
-        self._count_phn = self._count_words(text)
+        self._count_phn = self._count_words(text, separator.word)
 
     @abc.abstractmethod
     def process(self, text: List[str]) -> List[str]:
diff --git a/test/test_espeak_word_mismatch.py b/test/test_espeak_word_mismatch.py
index 5d77014..37ae0d3 100644
--- a/test/test_espeak_word_mismatch.py
+++ b/test/test_espeak_word_mismatch.py
@@ -5,8 +5,11 @@
 
 import pytest
 
-from phonemizer.backend.espeak.words_mismatch import Ignore
+import re
+
 from phonemizer import phonemize
+from phonemizer.backend.espeak.words_mismatch import Ignore
+from phonemizer.separator import Separator, default_separator
 
 
 @pytest.fixture
@@ -16,7 +19,8 @@ def text():
 
 def test_count_words():
     # pylint: disable=protected-access
-    count_words = Ignore._count_words
+    count_words = lambda phn: Ignore._count_words(
+        phn, wordsep=default_separator.word)
     assert count_words(['']) == [0]
     assert count_words(['a']) == [1]
     assert count_words(['aaa']) == [1]
@@ -59,3 +63,17 @@ def test_mismatch(caplog, text, mode):
             'words count mismatch on line 3 (expected 4 words but get 3)'
             in messages)
         assert 'words count mismatch on 67.0% of the lines (2/3)' in messages
+
+
+# from https://github.com/bootphon/phonemizer/issues/169
+def test_custom_separator(caplog):
+    phn = phonemize(
+        'try',
+        backend='espeak',
+        language='en-us',
+        separator=Separator(word='|', phone=' '),
+        words_mismatch='warn')
+
+    assert phn == 't ɹ aɪ |'
+    messages = [msg[2] for msg in caplog.record_tuples]
+    assert len(messages) == 0