diff --git a/components/collector/src/source_collectors/junit/tests.py b/components/collector/src/source_collectors/junit/tests.py
index 02b096a32b..2112e5091c 100644
--- a/components/collector/src/source_collectors/junit/tests.py
+++ b/components/collector/src/source_collectors/junit/tests.py
@@ -39,5 +39,8 @@ def _include_entity(self, entity: Entity) -> bool:
     @staticmethod
     def __entity(case_node: Element, case_result: str) -> Entity:
         """Transform a test case into a test case entity."""
+        class_name = case_node.get("classname", "")
         name = case_node.get("name", "<nameless test case>")
-        return Entity(key=name, name=name, class_name=case_node.get("classname", ""), test_result=case_result)
+        key = f"{class_name}:{name}"
+        old_key = name  # Key was changed after Quality-time 5.16.1, enable migration of user entity data
+        return Entity(key=key, old_key=old_key, name=name, class_name=class_name, test_result=case_result)
diff --git a/components/collector/tests/source_collectors/junit/test_tests.py b/components/collector/tests/source_collectors/junit/test_tests.py
index 9557b1430d..19ff01395e 100644
--- a/components/collector/tests/source_collectors/junit/test_tests.py
+++ b/components/collector/tests/source_collectors/junit/test_tests.py
@@ -12,11 +12,11 @@ def setUp(self):
         """Extend to set up JUnit test data."""
         super().setUp()
         self.expected_entities = [
-            {"key": "tc1", "name": "tc1", "class_name": "cn", "test_result": "passed"},
-            {"key": "tc2", "name": "tc2", "class_name": "cn", "test_result": "passed"},
-            {"key": "tc3", "name": "tc3", "class_name": "cn", "test_result": "failed"},
-            {"key": "tc4", "name": "tc4", "class_name": "cn", "test_result": "errored"},
-            {"key": "tc5", "name": "tc5", "class_name": "cn", "test_result": "skipped"},
+            {"key": "cn:tc1", "old_key": "tc1", "name": "tc1", "class_name": "cn", "test_result": "passed"},
+            {"key": "cn:tc2", "old_key": "tc2", "name": "tc2", "class_name": "cn", "test_result": "passed"},
+            {"key": "cn:tc3", "old_key": "tc3", "name": "tc3", "class_name": "cn", "test_result": "failed"},
+            {"key": "cn:tc4", "old_key": "tc4", "name": "tc4", "class_name": "cn", "test_result": "errored"},
+            {"key": "cn:tc5", "old_key": "tc5", "name": "tc5", "class_name": "cn", "test_result": "skipped"},
         ]
 
     async def test_tests(self):
@@ -32,7 +32,7 @@ async def test_failed_tests(self):
             response,
             value="1",
             total="5",
-            entities=[{"key": "tc3", "name": "tc3", "class_name": "cn", "test_result": "failed"}],
+            entities=[{"key": "cn:tc3", "old_key": "tc3", "name": "tc3", "class_name": "cn", "test_result": "failed"}],
         )
 
     async def test_zipped_junit_report(self):
@@ -45,3 +45,15 @@ async def test_empty_test_suites(self):
         """Test that a JUnit XML file with an empty testsuites node works."""
         response = await self.collect(get_request_text=self.JUNIT_XML_EMPTY_TEST_SUITES)
         self.assert_measurement(response, value="0", total="0")
+
+    async def test_repeated_test_case_names(self):
+        """Test that repeated test case names are distinguished."""
+        junit_xml_repeated_test_case_name = """<testsuites>
+        <testsuite timestamp="2009-12-19T17:58:59">
+            <testcase name="tc1" classname="cn1"/>
+            <testcase name="tc2" classname="cn1"/>
+            <testcase name="tc1" classname="cn2"/>
+            <testcase name="tc2" classname="cn2"/>
+        </testsuite></testsuites>"""
+        response = await self.collect(get_request_text=junit_xml_repeated_test_case_name)
+        self.assert_measurement(response, value="4", total="4")
diff --git a/docs/src/changelog.md b/docs/src/changelog.md
index 5bfea04b6f..72361964ab 100644
--- a/docs/src/changelog.md
+++ b/docs/src/changelog.md
@@ -8,6 +8,16 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 
 <!-- The line "## <square-bracket>Unreleased</square-bracket>" is replaced by the release/release.py script with the new release version and release date. -->
 
+## [Unreleased]
+
+### Deployment notes
+
+If your currently installed *Quality-time* version is not v5.16.1, please first check the upgrade path in the [versioning policy](versioning.md).
+
+### Fixed
+
+- The 'tests' metric with JUnit XML files as source would report incorrect results if the JUnit XML files contain test case names that are not unique across test suites. Fixes [#9872](https://github.com/ICTU/quality-time/issues/9872).
+
 ## v5.16.1 - 2024-09-26
 
 ### Deployment notes