diff --git a/Makefile b/Makefile
index 7dd7d06..6e06abf 100644
--- a/Makefile
+++ b/Makefile
@@ -1,13 +1,13 @@
+all:
+	@echo "Try 'make install'"
+
 test:
 	-@nilmtool destroy /lees-compressor/no-leak/raw/4 || true
 	-@nilmtool destroy /lees-compressor/no-leak/raw/16 || true
 	-@nilmtool create /lees-compressor/no-leak/raw/4 float32_18 || true
 	-@nilmtool create /lees-compressor/no-leak/raw/16 float32_18 || true
-	time python nilmtools/decimate.py -s '2013-02-04 18:10:00' -e '2013-02-04 18:11:00' /lees-compressor/no-leak/raw/1 /lees-compressor/no-leak/raw/4
-	python nilmtools/decimate.py -s '2013-02-04 18:10:00' -e '2013-02-04 18:11:00' /lees-compressor/no-leak/raw/4 /lees-compressor/no-leak/raw/16
-
-all:
-	@echo "Try 'make install'"
+	time python src/decimate.py -s '2013-02-04 18:10:00' -e '2013-02-04 18:11:00' /lees-compressor/no-leak/raw/1 /lees-compressor/no-leak/raw/4
+	python src/decimate.py -s '2013-02-04 18:10:00' -e '2013-02-04 18:11:00' /lees-compressor/no-leak/raw/4 /lees-compressor/no-leak/raw/16
 
 version:
 	python setup.py version
diff --git a/setup.py b/setup.py
index 91419c8..7a67f85 100755
--- a/setup.py
+++ b/setup.py
@@ -30,7 +30,7 @@ except ImportError:
 # Versioneer manages version numbers from git tags.
 # https://github.com/warner/python-versioneer
 import versioneer
-versioneer.versionfile_source = 'nilmtools/_version.py'
+versioneer.versionfile_source = 'src/_version.py'
 versioneer.versionfile_build = 'nilmtools/_version.py'
 versioneer.tag_prefix = 'nilmtools-'
 versioneer.parentdir_prefix = 'nilmtools-'
@@ -65,6 +65,7 @@ setup(name='nilmtools',
                            ],
       packages = [ 'nilmtools',
                    ],
+      package_dir = { 'nilmtools': 'src' },
       entry_points = {
           'console_scripts': [
               'nilm-decimate = nilmtools.decimate:main',
diff --git a/nilmtools/__init__.py b/src/__init__.py
similarity index 100%
rename from nilmtools/__init__.py
rename to src/__init__.py
diff --git a/nilmtools/_version.py b/src/_version.py
similarity index 99%
rename from nilmtools/_version.py
rename to src/_version.py
index f6a8c9c..4b95e1d 100644
--- a/nilmtools/_version.py
+++ b/src/_version.py
@@ -181,7 +181,7 @@ def versions_from_parentdir(parentdir_prefix, versionfile_source, verbose=False)
 
 tag_prefix = "nilmtools-"
 parentdir_prefix = "nilmtools-"
-versionfile_source = "nilmtools/_version.py"
+versionfile_source = "src/_version.py"
 
 def get_versions(default={"version": "unknown", "full": ""}, verbose=False):
     variables = { "refnames": git_refnames, "full": git_full }
diff --git a/nilmtools/copy.py b/src/copy.py
similarity index 100%
rename from nilmtools/copy.py
rename to src/copy.py
diff --git a/nilmtools/decimate.py b/src/decimate.py
similarity index 100%
rename from nilmtools/decimate.py
rename to src/decimate.py
diff --git a/nilmtools/filter.py b/src/filter.py
similarity index 100%
rename from nilmtools/filter.py
rename to src/filter.py
diff --git a/nilmtools/insert.py b/src/insert.py
similarity index 100%
rename from nilmtools/insert.py
rename to src/insert.py