diff --git a/command.py b/command.py
index 129919ca5..7da063a25 100644
--- a/command.py
+++ b/command.py
@@ -412,7 +412,8 @@ class Command:
             for project in all_projects_list:
                 if submodules_ok or project.sync_s:
                     derived_projects.update(
-                        (p.name, p) for p in project.GetDerivedSubprojects()
+                        (p.RelPath(local=False), p)
+                        for p in project.GetDerivedSubprojects()
                     )
             all_projects_list.extend(derived_projects.values())
             for project in all_projects_list:
diff --git a/tests/test_command.py b/tests/test_command.py
new file mode 100644
index 000000000..bd2a47f71
--- /dev/null
+++ b/tests/test_command.py
@@ -0,0 +1,88 @@
+# Copyright (C) 2026 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Unittests for the command.py module."""
+
+from command import Command
+
+
+class FakeProject:
+    """Minimal project double for Command.GetProjects tests."""
+
+    def __init__(
+        self,
+        name,
+        relpath,
+        *,
+        gitdir=None,
+        derived_subprojects=None,
+        sync_s=False,
+    ):
+        self.name = name
+        self.relpath = relpath
+        self.gitdir = gitdir or f"/git/{relpath}"
+        self.sync_s = sync_s
+        self.Exists = True
+        self._derived_subprojects = derived_subprojects or []
+
+    def GetDerivedSubprojects(self):
+        return list(self._derived_subprojects)
+
+    def MatchesGroups(self, _groups):
+        return True
+
+    def RelPath(self, local=True):
+        return self.relpath
+
+
+class FakeManifest:
+    """Minimal manifest double for Command.GetProjects tests."""
+
+    def __init__(self, projects):
+        self.projects = projects
+
+    def GetManifestGroupsStr(self):
+        return "default"
+
+
+def test_get_projects_keeps_derived_subprojects_for_repeated_repo():
+    """Derived subprojects are keyed by checkout path, not repo identity."""
+    submodule_a = FakeProject(
+        "submodule",
+        "src/one/submodule",
+        gitdir="/shared/modules/submodule.git",
+    )
+    submodule_b = FakeProject(
+        "submodule",
+        "src/two/submodule",
+        gitdir="/shared/modules/submodule.git",
+    )
+    project_a = FakeProject(
+        "project",
+        "src/one",
+        derived_subprojects=[submodule_a],
+        sync_s=True,
+    )
+    project_b = FakeProject(
+        "project",
+        "src/two",
+        derived_subprojects=[submodule_b],
+        sync_s=True,
+    )
+    manifest = FakeManifest([project_a, project_b])
+    cmd = Command(manifest=manifest)
+
+    projects = cmd.GetProjects([])
+
+    assert set(projects) == {project_a, project_b, submodule_a, submodule_b}