diff --git a/datasette/utils/asyncdi.py b/datasette/utils/asyncdi.py
index 4c7f3a60..ba743450 100644
--- a/datasette/utils/asyncdi.py
+++ b/datasette/utils/asyncdi.py
@@ -8,13 +8,23 @@ except ImportError:
     from . import vendored_graphlib as graphlib
 
 
+def inject(fn):
+    fn._inject = True
+    return fn
+
+
 class AsyncMeta(type):
     def __new__(cls, name, bases, attrs):
         # Decorate any items that are 'async def' methods
         _registry = {}
         new_attrs = {"_registry": _registry}
+        inject_all = attrs.get("inject_all")
         for key, value in attrs.items():
-            if inspect.iscoroutinefunction(value) and not value.__name__ == "resolve":
+            if (
+                inspect.iscoroutinefunction(value)
+                and not value.__name__ == "resolve"
+                and (inject_all or getattr(value, "_inject", None))
+            ):
                 new_attrs[key] = make_method(value)
                 _registry[key] = new_attrs[key]
             else:
diff --git a/tests/test_asyncdi.py b/tests/test_asyncdi.py
index 68dcb2fd..baf8a469 100644
--- a/tests/test_asyncdi.py
+++ b/tests/test_asyncdi.py
@@ -1,5 +1,5 @@
 import asyncio
-from datasette.utils.asyncdi import AsyncBase
+from datasette.utils.asyncdi import AsyncBase, inject
 import pytest
 from random import random
 
@@ -8,15 +8,22 @@ class Simple(AsyncBase):
     def __init__(self):
         self.log = []
 
+    @inject
     async def two(self):
         self.log.append("two")
 
+    @inject
     async def one(self, two):
         self.log.append("one")
         return self.log
 
+    async def not_inject(self, one, two):
+        return one + two
+
 
 class Complex(AsyncBase):
+    inject_all = True
+
     def __init__(self):
         self.log = []
 
@@ -40,6 +47,8 @@ class Complex(AsyncBase):
 
 
 class WithParameters(AsyncBase):
+    inject_all = True
+
     async def go(self, calc1, calc2, param1):
         return param1 + calc1 + calc2
 
@@ -53,6 +62,7 @@ class WithParameters(AsyncBase):
 @pytest.mark.asyncio
 async def test_simple():
     assert await Simple().one() == ["two", "one"]
+    assert await Simple().not_inject(6, 7) == 13
 
 
 @pytest.mark.asyncio