diff --git a/README.md b/README.md
index 4c8f80f..7fd9f6a 100644
--- a/README.md
+++ b/README.md
@@ -50,6 +50,24 @@ The HTTP requests to `www.example.com` and `simonwillison.net` will be performed
 
 The library notices that `both()` takes two arguments which are the names of other registered `async def` functions, and will construct an execution plan that executes those two functions in parallel, then passes their results to the `both()` method.
 
+### Registering additional functions
+
+In addition to registering functions by passing them to the constructor, you can also add them to a registry using the `.register()` method:
+
+```python
+async def another():
+    return "another"
+
+registry.register(another)
+```
+To register them with a name other than the name of the function, pass the `name=` argument:
+```python
+async def another():
+    return "another 2"
+
+registry.register(another, name="another_2")
+```
+
 ### Resolving an unregistered function
 
 You don't need to register the final function that you pass to `.resolve()` - if you pass an unregistered function, the library will introspect the function's parameters and resolve them directly.
diff --git a/asyncinject/__init__.py b/asyncinject/__init__.py
index de69bd5..a553660 100644
--- a/asyncinject/__init__.py
+++ b/asyncinject/__init__.py
@@ -18,8 +18,8 @@ def __init__(self, *fns, parallel=True, timer=None):
         for fn in fns:
             self.register(fn)
 
-    def register(self, fn):
-        self._registry[fn.__name__] = fn
+    def register(self, fn, *, name=None):
+        self._registry[name or fn.__name__] = fn
         # Clear caches:
         self._graph = None
         self._reversed = None
diff --git a/tests/test_asyncinject.py b/tests/test_asyncinject.py
index ad62722..fdd3318 100644
--- a/tests/test_asyncinject.py
+++ b/tests/test_asyncinject.py
@@ -181,3 +181,29 @@ def three_not_async(one, two):
     # Test that passing parameters works too
     result2 = await registry.resolve(fn, one=2)
     assert result2 == 4
+
+
+@pytest.mark.asyncio
+async def test_register():
+    registry = Registry()
+
+    async def one():
+        return "one"
+
+    async def two_():
+        return "two"
+
+    async def three(one, two):
+        return one + two
+
+    registry.register(one)
+
+    # Should raise an error if you don't use name=
+    with pytest.raises(TypeError):
+        registry.register(two_, "two")
+
+    registry.register(two_, name="two")
+
+    result = await registry.resolve(three)
+
+    assert result == "onetwo"