diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 4127d4e..3190c97 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -5,6 +5,7 @@ Changelog
 TBA
 ===
 
+* To match how we group test cases, JUnit output ``failures`` count is now the amount of files with errors. (#431)
 * Fixed a whitespace/newline false positive for control conditions containing lambdas. (#410)
 
 2.0.2 (2025-04-08)
diff --git a/cpplint.py b/cpplint.py
index 07687d2..e02c614 100755
--- a/cpplint.py
+++ b/cpplint.py
@@ -1547,7 +1547,7 @@ def AddJUnitFailure(self, filename, linenum, message, category, confidence):
 
     def FormatJUnitXML(self):
         num_errors = len(self._junit_errors)
-        num_failures = len(self._junit_failures)
+        num_failures = len({failure[0] for failure in self._junit_failures})
 
         testsuite = xml.etree.ElementTree.Element("testsuite")
         testsuite.attrib["errors"] = str(num_errors)
diff --git a/cpplint_unittest.py b/cpplint_unittest.py
index d568251..d189a3d 100755
--- a/cpplint_unittest.py
+++ b/cpplint_unittest.py
@@ -5071,7 +5071,7 @@ def testJUnitXML(self):
             ]
             expected = (
                 '<?xml version="1.0" encoding="UTF-8" ?>\n'
-                '<testsuite errors="0" failures="3" name="cpplint" tests="3">'
+                '<testsuite errors="0" failures="2" name="cpplint" tests="2">'
                 '<testcase name="File1"><failure>5: FailMsg1 [category/subcategory]'
                 " [3]\n19: FailMsg3 [category/subcategory] [3]</failure></testcase>"
                 '<testcase name="File2"><failure>99: FailMsg2 '
diff --git a/samples/silly-sample/junit.def b/samples/silly-sample/junit.def
index c4dce11..30bca44 100644
--- a/samples/silly-sample/junit.def
+++ b/samples/silly-sample/junit.def
@@ -3,7 +3,7 @@
 1
 
 <?xml version="1.0" encoding="UTF-8" ?>
-<testsuite errors="0" failures="123" name="cpplint" tests="123"><testcase name="src/sillycode.cpp"><failure>0: No copyright message found.  You should have a line: "Copyright [year] &lt;Copyright Owner&gt;" [legal/copyright] [5]
+<testsuite errors="0" failures="2" name="cpplint" tests="2"><testcase name="src/sillycode.cpp"><failure>0: No copyright message found.  You should have a line: "Copyright [year] &lt;Copyright Owner&gt;" [legal/copyright] [5]
 1: Include the directory when naming header files [build/include_subdir] [4]
 3: At least two spaces is best between code and comments [whitespace/comments] [2]
 3: Should have a space between // and comment [whitespace/comments] [4]