diff --git a/changelog.d/20260106_193940_sirosen_fix_typing_strictness_bug.rst b/changelog.d/20260106_193940_sirosen_fix_typing_strictness_bug.rst
new file mode 100644
index 000000000..50fc6f99b
--- /dev/null
+++ b/changelog.d/20260106_193940_sirosen_fix_typing_strictness_bug.rst
@@ -0,0 +1,6 @@
+Fixed
+-----
+
+- The type of ``scope_requirements`` in the init signature for ``ClientApp``
+  has been expanded to ``typing.Mapping`` to match other locations where a
+  ``scope_requirements`` mapping is accepted. (:pr:`NUMBER`)
diff --git a/src/globus_sdk/globus_app/client_app.py b/src/globus_sdk/globus_app/client_app.py
index 4718099c0..f8974beed 100644
--- a/src/globus_sdk/globus_app/client_app.py
+++ b/src/globus_sdk/globus_app/client_app.py
@@ -61,7 +61,7 @@ def __init__(
         client_id: uuid.UUID | str | None = None,
         client_secret: str | None = None,
         scope_requirements: (
-            dict[str, str | Scope | t.Iterable[str | Scope]] | None
+            t.Mapping[str, str | Scope | t.Iterable[str | Scope]] | None
         ) = None,
         config: GlobusAppConfig = DEFAULT_CONFIG,
     ) -> None:
diff --git a/tests/non-pytest/mypy-ignore-tests/app_scope_requirements.py b/tests/non-pytest/mypy-ignore-tests/app_scope_requirements.py
index b49b214c5..3b9143245 100644
--- a/tests/non-pytest/mypy-ignore-tests/app_scope_requirements.py
+++ b/tests/non-pytest/mypy-ignore-tests/app_scope_requirements.py
@@ -1,4 +1,9 @@
-from globus_sdk import UserApp
+from types import MappingProxyType
+
+from globus_sdk import ClientApp, UserApp
+
+my_user_app = UserApp("...", client_id="...")
+my_client_app = ClientApp("...", client_id="...", client_secret="...")
 
 # declare scope data in the form of a subtype of the
 # `str | Scope | t.Iterable[str | Scope]` (`list[str]`) indexed in a dict,
@@ -9,5 +14,26 @@
 # `dict[str, str | Scope | t.Iterable[str | Scope]]` which will reject the input
 # type because `dict` is a mutable container, and therefore invariant
 scopes: dict[str, list[str]] = {"foo": ["bar"]}
-my_app = UserApp("...", client_id="...")
-my_app.add_scope_requirements(scopes)
+my_user_app.add_scope_requirements(scopes)
+my_client_app.add_scope_requirements(scopes)
+
+# a mapping proxy is an immutable mapping (proxy) and should be accepted by apps as well
+# meaning that any mapping is fine, not just `dict` specifically (or MutableMapping)
+my_user_app.add_scope_requirements(MappingProxyType(scopes))
+my_client_app.add_scope_requirements(MappingProxyType(scopes))
+
+
+# both of the above tests repeated, but now on init
+my_user_app = UserApp("...", client_id="...", scope_requirements=scopes)
+my_user_app = UserApp(
+    "...", client_id="...", scope_requirements=MappingProxyType(scopes)
+)
+my_client_app = ClientApp(
+    "...", client_id="...", client_secret="...", scope_requirements=scopes
+)
+my_client_app = ClientApp(
+    "...",
+    client_id="...",
+    client_secret="...",
+    scope_requirements=MappingProxyType(scopes),
+)