diff --git a/src/poetry/core/packages/dependency_group.py b/src/poetry/core/packages/dependency_group.py
index 679e9d387..c808958bd 100644
--- a/src/poetry/core/packages/dependency_group.py
+++ b/src/poetry/core/packages/dependency_group.py
@@ -169,8 +169,9 @@ def __eq__(self, other: object) -> bool:
 
         return (
             self._name == other.name
-            and set(self._dependencies) == set(other.dependencies)
+            and set(self._dependencies) == set(other._dependencies)
             and set(self._poetry_dependencies) == set(other._poetry_dependencies)
+            and self._included_dependency_groups == other._included_dependency_groups
         )
 
     def __repr__(self) -> str:
diff --git a/tests/packages/test_dependency_group.py b/tests/packages/test_dependency_group.py
index 88d779136..e6c3da776 100644
--- a/tests/packages/test_dependency_group.py
+++ b/tests/packages/test_dependency_group.py
@@ -644,3 +644,17 @@ def test_include_dependency_group_raise_if_already_included(group_name: str) ->
         ValueError, match=f"Dependency group {group_name} is already included"
     ):
         group.include_dependency_group(group_3)
+
+
+def test_dependency_group_inequality() -> None:
+    a = DependencyGroup(name="test")
+    a.add_dependency(Dependency(name="dep1", constraint="*"))
+
+    b = DependencyGroup(name="test")
+    b.add_dependency(Dependency(name="dep1", constraint="*"))
+    extras = DependencyGroup(name="extras")
+    extras.add_dependency(Dependency(name="dep2", constraint="*"))
+    b.include_dependency_group(extras)
+
+    assert a != b
+    assert b != a