diff --git a/setup.cfg b/setup.cfg
index e584ee7c..6dbbeee8 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -19,7 +19,7 @@ source =
 
 [coverage:paths]
 source =
-    flask
+    src/flask
     .tox/*/lib/python*/site-packages/flask
     .tox/pypy/site-packages/flask
 
@@ -46,4 +46,4 @@ max-line-length = 80
 per-file-ignores =
     # __init__ modules export names
     **/__init__.py: F401
-    **/_compat.py: E731, B301, F401
+    src/flask/_compat.py: E731, B301, F401
diff --git a/setup.py b/setup.py
index 531dbca1..36e9a72b 100755
--- a/setup.py
+++ b/setup.py
@@ -4,12 +4,13 @@ import io
 import re
 from collections import OrderedDict
 
+from setuptools import find_packages
 from setuptools import setup
 
 with io.open("README.rst", "rt", encoding="utf8") as f:
     readme = f.read()
 
-with io.open("flask/__init__.py", "rt", encoding="utf8") as f:
+with io.open("src/flask/__init__.py", "rt", encoding="utf8") as f:
     version = re.search(r"__version__ = \"(.*?)\"", f.read()).group(1)
 
 setup(
@@ -30,7 +31,8 @@ setup(
     maintainer_email="contact@palletsprojects.com",
     description="A simple framework for building complex web applications.",
     long_description=readme,
-    packages=["flask", "flask.json"],
+    packages=find_packages("src"),
+    package_dir={"": "src"},
     include_package_data=True,
     zip_safe=False,
     platforms="any",
diff --git a/flask/__init__.py b/src/flask/__init__.py
similarity index 100%
rename from flask/__init__.py
rename to src/flask/__init__.py
diff --git a/flask/__main__.py b/src/flask/__main__.py
similarity index 100%
rename from flask/__main__.py
rename to src/flask/__main__.py
diff --git a/flask/_compat.py b/src/flask/_compat.py
similarity index 100%
rename from flask/_compat.py
rename to src/flask/_compat.py
diff --git a/flask/app.py b/src/flask/app.py
similarity index 100%
rename from flask/app.py
rename to src/flask/app.py
diff --git a/flask/blueprints.py b/src/flask/blueprints.py
similarity index 100%
rename from flask/blueprints.py
rename to src/flask/blueprints.py
diff --git a/flask/cli.py b/src/flask/cli.py
similarity index 100%
rename from flask/cli.py
rename to src/flask/cli.py
diff --git a/flask/config.py b/src/flask/config.py
similarity index 100%
rename from flask/config.py
rename to src/flask/config.py
diff --git a/flask/ctx.py b/src/flask/ctx.py
similarity index 100%
rename from flask/ctx.py
rename to src/flask/ctx.py
diff --git a/flask/debughelpers.py b/src/flask/debughelpers.py
similarity index 100%
rename from flask/debughelpers.py
rename to src/flask/debughelpers.py
diff --git a/flask/globals.py b/src/flask/globals.py
similarity index 100%
rename from flask/globals.py
rename to src/flask/globals.py
diff --git a/flask/helpers.py b/src/flask/helpers.py
similarity index 100%
rename from flask/helpers.py
rename to src/flask/helpers.py
diff --git a/flask/json/__init__.py b/src/flask/json/__init__.py
similarity index 100%
rename from flask/json/__init__.py
rename to src/flask/json/__init__.py
diff --git a/flask/json/tag.py b/src/flask/json/tag.py
similarity index 100%
rename from flask/json/tag.py
rename to src/flask/json/tag.py
diff --git a/flask/logging.py b/src/flask/logging.py
similarity index 100%
rename from flask/logging.py
rename to src/flask/logging.py
diff --git a/flask/sessions.py b/src/flask/sessions.py
similarity index 100%
rename from flask/sessions.py
rename to src/flask/sessions.py
diff --git a/flask/signals.py b/src/flask/signals.py
similarity index 100%
rename from flask/signals.py
rename to src/flask/signals.py
diff --git a/flask/templating.py b/src/flask/templating.py
similarity index 100%
rename from flask/templating.py
rename to src/flask/templating.py
diff --git a/flask/testing.py b/src/flask/testing.py
similarity index 100%
rename from flask/testing.py
rename to src/flask/testing.py
diff --git a/flask/views.py b/src/flask/views.py
similarity index 100%
rename from flask/views.py
rename to src/flask/views.py
diff --git a/flask/wrappers.py b/src/flask/wrappers.py
similarity index 100%
rename from flask/wrappers.py
rename to src/flask/wrappers.py