diff --git a/injections/__init__.py b/injections/__init__.py
index 47bdc0d..dce8a9e 100644
--- a/injections/__init__.py
+++ b/injections/__init__.py
@@ -1,6 +1,7 @@
 from .core import (
     Container,
     Dependency,
+    MissingDependencyError,
     has,
     depends,
     propagate,
@@ -11,6 +12,7 @@ from .core import (
 __all__ = [
     'Container',
     'Dependency',
+    'MissingDependencyError',
     'has',
     'depends',
     'propagate',
diff --git a/injections/core.py b/injections/core.py
index a4dccae..edff1db 100644
--- a/injections/core.py
+++ b/injections/core.py
@@ -76,6 +76,13 @@ class Dependency:
 depends = Dependency  # nicer declarative name
 
 
+class MissingDependencyError(KeyError):
+    """Required dependency is missed in container"""
+
+    def __str__(self):
+        return "Dependency {!r} is missed in container".format(self.args[0])
+
+
 class Container(object):
     """Container for things that will be dependency-injected
 
@@ -104,7 +111,10 @@ class Container(object):
         deps = getattr(inst, '__injections__', None)
         if deps:
             for attr, dep in deps.items():
-                val = pro[dep.name]
+                val = pro.get(dep.name)
+                if val is None:
+                    raise MissingDependencyError(dep.name)
+
                 if not isinstance(val, dep.type):
                     raise TypeError("Wrong provider for {!r}".format(val))
                 setattr(inst, attr, val)
diff --git a/setup.py b/setup.py
index 41cf797..c1e7d04 100644
--- a/setup.py
+++ b/setup.py
@@ -16,4 +16,5 @@ setup(name='injections',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 2',
         ],
+      license='MIT',
      )

Use custom exception for injecting container into object with unknown dependencies
I have a class
```
@has
class A:
    redis = depends(Redis)
    loop = depends(AbstractLoop)
```

When I try to initialize it from container with missing dependencies I have a `KeyError`.
```
inj = Container()
inj['redis'] = create_redis()
inj.inject(A())  # raises KeyError
```

Exception on injection stage is pretty cool but I suggest using custom exception class. Not `KeyError` but derived from it. Exception text also should be more informative than just `KeyError: 'loop'`.
diff --git a/injections/test_core.py b/injections/test_core.py
index 2e9aabe..06006cd 100644
--- a/injections/test_core.py
+++ b/injections/test_core.py
@@ -126,3 +126,21 @@ class TestCore(TestCase):
         c['name'] = 1
         with self.assertRaises(TypeError):
             c.inject(self.Consumer())
+
+    def test_missing_dependency(self):
+        c = di.Container()
+        c['a'] = 1
+
+        @di.has
+        class Consumer:
+            a = di.depends(int)
+            b = di.depends(int)
+
+        if hasattr(self, 'assertRaisesRegex'):
+            checker = self.assertRaisesRegex
+        else:
+            checker = self.assertRaisesRegexp
+
+        with checker(di.MissingDependencyError,
+                     "Dependency 'b' is missed in container"):
+            c.inject(Consumer())

pip install -e .
parse_log_pytest
pytest
nose pytest
3.4
pytest --no-header -rA --tb=line --color=no -p no:cacheprovider -W ignore::DeprecationWarning
attrs @ file:///opt/conda/conda-bld/attrs_1642510447205/work
certifi==2021.5.30
importlib-metadata @ file:///tmp/build/80754af9/importlib-metadata_1631916693255/work
iniconfig @ file:///home/linux1/recipes/ci/iniconfig_1610983019677/work
-e git+https://github.com/tailhook/injections.git@680d3403f0086e0a94d69604bba0bfcbd9596014#egg=injections
more-itertools @ file:///tmp/build/80754af9/more-itertools_1637733554872/work
nose==1.3.7
packaging @ file:///tmp/build/80754af9/packaging_1637314298585/work
pluggy @ file:///tmp/build/80754af9/pluggy_1615976315926/work
py @ file:///opt/conda/conda-bld/py_1644396412707/work
pyparsing @ file:///tmp/build/80754af9/pyparsing_1635766073266/work
pytest==6.2.4
toml @ file:///tmp/build/80754af9/toml_1616166611790/work
typing_extensions @ file:///opt/conda/conda-bld/typing_extensions_1647553014482/work
zipp @ file:///tmp/build/80754af9/zipp_1633618647012/work

name: injections
channels:
  - defaults
  - https://repo.anaconda.com/pkgs/main
  - https://repo.anaconda.com/pkgs/r
  - conda-forge
dependencies:
  - _libgcc_mutex=0.1=main
  - _openmp_mutex=5.1=1_gnu
  - attrs=21.4.0=pyhd3eb1b0_0
  - ca-certificates=2025.2.25=h06a4308_0
  - certifi=2021.5.30=py36h06a4308_0
  - importlib-metadata=4.8.1=py36h06a4308_0
  - importlib_metadata=4.8.1=hd3eb1b0_0
  - iniconfig=1.1.1=pyhd3eb1b0_0
  - ld_impl_linux-64=2.40=h12ee557_0
  - libffi=3.3=he6710b0_2
  - libgcc-ng=11.2.0=h1234567_1
  - libgomp=11.2.0=h1234567_1
  - libstdcxx-ng=11.2.0=h1234567_1
  - more-itertools=8.12.0=pyhd3eb1b0_0
  - ncurses=6.4=h6a678d5_0
  - openssl=1.1.1w=h7f8727e_0
  - packaging=21.3=pyhd3eb1b0_0
  - pip=21.2.2=py36h06a4308_0
  - pluggy=0.13.1=py36h06a4308_0
  - py=1.11.0=pyhd3eb1b0_0
  - pyparsing=3.0.4=pyhd3eb1b0_0
  - pytest=6.2.4=py36h06a4308_2
  - python=3.6.13=h12debd9_1
  - readline=8.2=h5eee18b_0
  - setuptools=58.0.4=py36h06a4308_0
  - sqlite=3.45.3=h5eee18b_0
  - tk=8.6.14=h39e8969_0
  - toml=0.10.2=pyhd3eb1b0_0
  - typing_extensions=4.1.1=pyh06a4308_0
  - wheel=0.37.1=pyhd3eb1b0_0
  - xz=5.6.4=h5eee18b_1
  - zipp=3.6.0=pyhd3eb1b0_0
  - zlib=1.2.13=h5eee18b_1
  - pip:
      - nose==1.3.7
prefix: /opt/conda/envs/injections

injections/test_core.py::TestCore::test_missing_dependency
injections/test_core.py::TestCore::test_clone injections/test_core.py::TestCore::test_cyclic injections/test_core.py::TestCore::test_interconnect injections/test_core.py::TestCore::test_larger_cycle injections/test_core.py::TestCore::test_ok injections/test_core.py::TestCore::test_wrong_type
setup.py injections/core.py injections/__init__.py
setup.py injections/core.py injections/__init__.py