diff --git a/presidio-analyzer/presidio_analyzer/predefined_recognizers/country_specific/spain/es_nie_recognizer.py b/presidio-analyzer/presidio_analyzer/predefined_recognizers/country_specific/spain/es_nie_recognizer.py
index cc8a9601a3..a88cb15ea0 100644
--- a/presidio-analyzer/presidio_analyzer/predefined_recognizers/country_specific/spain/es_nie_recognizer.py
+++ b/presidio-analyzer/presidio_analyzer/predefined_recognizers/country_specific/spain/es_nie_recognizer.py
@@ -66,7 +66,7 @@ def validate_result(self, pattern_text: str) -> bool:
         letter = pattern_text[-1]
 
         # check last is a letter, and first is in X,Y,Z
-        if not pattern_text[1:-1].isdigit or pattern_text[:1] not in "XYZ":
+        if not pattern_text[1:-1].isdigit() or pattern_text[:1] not in "XYZ":
             return False
         # check size is 8 or 9
         if len(pattern_text) < 8 or len(pattern_text) > 9:
diff --git a/presidio-analyzer/tests/test_es_nie_recognizer.py b/presidio-analyzer/tests/test_es_nie_recognizer.py
index 0b91d1b98e..070d83fbeb 100644
--- a/presidio-analyzer/tests/test_es_nie_recognizer.py
+++ b/presidio-analyzer/tests/test_es_nie_recognizer.py
@@ -1,7 +1,8 @@
 import pytest
+from presidio_analyzer import Pattern
+from presidio_analyzer.predefined_recognizers import EsNieRecognizer
 
 from tests import assert_result
-from presidio_analyzer.predefined_recognizers import EsNieRecognizer
 
 
 @pytest.fixture(scope="module")
@@ -51,3 +52,11 @@ def test_when_all_es_nie_then_succeed(
     assert len(results) == expected_len
     for res, (st_pos, fn_pos) in zip(results, expected_positions):
         assert_result(res, entities[0], st_pos, fn_pos, max_score)
+
+
+def test_when_custom_pattern_allows_non_digit_middle_then_no_crash(entities):
+    """A non-digit middle segment should be rejected, not raise."""
+    loose_pattern = Pattern("NIE_LOOSE", r"\b[X-Z][0-9A-Za-z]{6}[A-Z]\b", 0.5)
+    recognizer = EsNieRecognizer(patterns=[loose_pattern])
+    results = recognizer.analyze("XABCDEFG", entities)
+    assert results == []