diff --git a/.gitignore b/.gitignore
index 9743be3..216189a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,10 +10,10 @@ dist/
 
 wheelhouse/
 
-pymmcore/pymmcore_swig_wrap.h
-pymmcore/pymmcore_swig_wrap.cpp
-pymmcore/_pymmcore_swig.cpython*
-pymmcore/pymmcore_swig.py
+src/pymmcore/pymmcore_swig_wrap.h
+src/pymmcore/pymmcore_swig_wrap.cpp
+src/pymmcore/_pymmcore_swig.*
+src/pymmcore/pymmcore_swig.py
 pymmcore.egg-info
 .mypy_cache/
 
diff --git a/maintainer-notes.md b/maintainer-notes.md
index a0b1f79..f5107e8 100644
--- a/maintainer-notes.md
+++ b/maintainer-notes.md
@@ -79,11 +79,11 @@ prefixed to the version:
 ```bash
 git checkout main
 
-vim pymmcore/_version.py  # Remove .dev0
+vim src/pymmcore/_version.py  # Remove .dev0
 git commit -a -m 'Version 1.2.3.42.4'
 git tag -a v1.2.3.42.4 -m Release
 
-vim pymmcore/_version.py  # Set version to 1.2.3.42.5.dev0
+vim src/pymmcore/_version.py  # Set version to 1.2.3.42.5.dev0
 git commit -a -m 'Version back to dev'
 
 git push upstream --follow-tags
diff --git a/pyproject.toml b/pyproject.toml
index c32d6f4..5bc331d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -32,12 +32,11 @@ dependencies = ["numpy >=1.12.0"]
 homepage = "https://micro-manager.org"
 repository = "https://github.com/micro-manager/pymmcore"
 
-
 [tool.setuptools.dynamic]
 version = { attr = "pymmcore._version.__version__" }
 
-[tool.setuptools.packages.find]
-include = ["pymmcore*"]
+[tool.setuptools.package-dir]
+"" = "src"
 
 [tool.setuptools.package-data]
 "*" = ["py.typed", ".pyi"]
diff --git a/setup.py b/setup.py
index 5a288da..bb14b7f 100644
--- a/setup.py
+++ b/setup.py
@@ -101,7 +101,9 @@ def run(self):
 
 mmcore_extension = Extension(
     f"{PKG_NAME}._{SWIG_MOD_NAME}",
-    sources=mmcore_sources + [os.path.join(PKG_NAME, f"{SWIG_MOD_NAME}.i")],
+    sources=mmcore_sources + [os.path.join(
+        "src", PKG_NAME, f"{SWIG_MOD_NAME}.i",
+    )],
     swig_opts=[
         "-c++",
         "-py3",
diff --git a/pymmcore/__init__.py b/src/pymmcore/__init__.py
similarity index 100%
rename from pymmcore/__init__.py
rename to src/pymmcore/__init__.py
diff --git a/pymmcore/__init__.pyi b/src/pymmcore/__init__.pyi
similarity index 100%
rename from pymmcore/__init__.pyi
rename to src/pymmcore/__init__.pyi
diff --git a/pymmcore/_version.py b/src/pymmcore/_version.py
similarity index 100%
rename from pymmcore/_version.py
rename to src/pymmcore/_version.py
diff --git a/pymmcore/py.typed b/src/pymmcore/py.typed
similarity index 100%
rename from pymmcore/py.typed
rename to src/pymmcore/py.typed
diff --git a/pymmcore/pymmcore_swig.i b/src/pymmcore/pymmcore_swig.i
similarity index 100%
rename from pymmcore/pymmcore_swig.i
rename to src/pymmcore/pymmcore_swig.i