diff --git a/injector/__init__.py b/injector/__init__.py
index 55f7ab2..45f5590 100644
--- a/injector/__init__.py
+++ b/injector/__init__.py
@@ -53,7 +53,7 @@
 log = logging.getLogger('injector')
 log.addHandler(logging.NullHandler())
 
-if log.level == logging.NOTSET:
+if log.level == logging.NOTSET:  # pragma: no branch
     log.setLevel(logging.WARN)
 
 T = TypeVar('T')
diff --git a/injector_100_percent_coverage_test.py b/injector_100_percent_coverage_test.py
new file mode 100644
index 0000000..4ceb26c
--- /dev/null
+++ b/injector_100_percent_coverage_test.py
@@ -0,0 +1,128 @@
+"""Targeted tests that exercise the remaining uncovered lines in ``injector``.
+
+These cases don't fit naturally into the functional test suite in
+``injector_test.py`` – they poke at internal string-formatting helpers and
+rarely-hit edge-case/error branches purely to drive coverage to 100%.
+"""
+
+from typing import Dict, List, Union
+
+import pytest
+
+import injector
+from injector import (
+    CallError,
+    Injector,
+    Module,
+    NoInject,
+    UnknownProvider,
+    UnsatisfiedRequirement,
+    provider,
+    singleton,
+)
+
+# --- String / representation formatting --------------------------------------
+
+
+def test_unsatisfied_requirement_str_without_owner():
+    # The ``self.owner`` falsy branch of ``UnsatisfiedRequirement.__str__``.
+    error = UnsatisfiedRequirement(None, int)
+    assert str(error) == 'unsatisfied requirement on int'
+
+
+def test_unsatisfied_requirement_str_with_owner():
+    # The ``self.owner`` truthy branch, which prepends a description of the owner.
+    class Owner:
+        pass
+
+    owner = Owner()
+    error = UnsatisfiedRequirement(owner, int)
+    message = str(error)
+    assert message.endswith('has an unsatisfied requirement on int')
+    assert message != 'unsatisfied requirement on int'
+
+
+def test_describe_named_object():
+    # Objects exposing ``__name__`` are described by that name.
+    assert injector._describe(int) == 'int'
+
+
+def test_describe_tuple_uses_first_element():
+    # Tuples/lists are described via their first element's ``__name__``.
+    assert injector._describe((int,)) == '[int]'
+    assert injector._describe([str]) == '[str]'
+
+
+def test_describe_falls_back_to_str():
+    # Anything without ``__name__`` that isn't a tuple/list falls back to ``str``.
+    assert injector._describe(123) == '123'
+
+
+def test_get_origin_normalizes_typing_aliases():
+    # Some (older) typings store ``typing.List``/``typing.Dict`` as ``__origin__``;
+    # ``_get_origin`` normalizes those back to the builtin containers.
+    class FakeListAlias:
+        __origin__ = List
+
+    class FakeDictAlias:
+        __origin__ = Dict
+
+    assert injector._get_origin(FakeListAlias) is list
+    assert injector._get_origin(FakeDictAlias) is dict
+
+
+# --- Edge-case exception / branch paths --------------------------------------
+
+
+def test_provider_for_unknown_target_raises():
+    # Neither a class, callable, provider nor a recognized bindable instance –
+    # provider_for can't figure out what to do and raises UnknownProvider.
+    binder = Injector().binder
+    with pytest.raises(UnknownProvider):
+        binder.provider_for(123, to=123)
+
+
+def test_unresolvable_forward_reference_in_provider_raises_name_error():
+    # The return annotation is a forward reference to a name that never exists,
+    # so it stays "__deferred__" and re-evaluation at configure time fails.
+    class BrokenModule(Module):
+        @provider
+        def provide(self) -> 'ThisNameNeverExists':  # noqa: F821
+            return object()
+
+    with pytest.raises(NameError, match='forward reference'):
+        Injector([BrokenModule])
+
+
+def test_create_object_wraps_new_type_error_in_call_error():
+    # ``cls.__new__(cls)`` raises TypeError (extra required arg), which gets
+    # re-raised as a CallError.
+    class NeedsArg:
+        def __new__(cls, required):
+            return super().__new__(cls)
+
+    with pytest.raises(CallError):
+        Injector().create_object(NeedsArg)
+
+
+def test_union_member_marked_noinject_is_dropped():
+    # A Union whose members carry the NoInject marker is removed from the
+    # inferred bindings.
+    def target(x: Union[NoInject[int], str]):
+        pass
+
+    bindings = injector._infer_injected_bindings(target, only_explicit_bindings=False)
+    assert 'x' not in bindings
+
+
+def test_get_with_scope_decorator_unwraps_to_scope():
+    # Passing a ScopeDecorator (e.g. ``singleton``) to Injector.get unwraps it
+    # to the underlying scope before resolving.
+    class Service:
+        pass
+
+    inj = Injector()
+    first = inj.get(Service, scope=singleton)
+    second = inj.get(Service, scope=singleton)
+    assert isinstance(first, Service)
+    assert first is second
diff --git a/pytest.ini b/pytest.ini
index cf7ece3..7cedea3 100644
--- a/pytest.ini
+++ b/pytest.ini
@@ -1,3 +1,3 @@
 [pytest]
-addopts = -v --tb=native --doctest-glob=*.md --doctest-modules --cov-report term --cov-report html --cov-report xml --cov=injector --cov-branch --cov-fail-under=90
+addopts = -v --tb=native --doctest-glob=*.md --doctest-modules --cov-report term --cov-report html --cov-report xml --cov=injector --cov-branch --cov-fail-under=100
 norecursedirs = __pycache__ *venv* .git build