diff --git a/src/Nirum/Targets/Python.hs b/src/Nirum/Targets/Python.hs
index 49f724c..7a76711 100644
--- a/src/Nirum/Targets/Python.hs
+++ b/src/Nirum/Targets/Python.hs
@@ -31,6 +31,7 @@ module Nirum.Targets.Python ( Code
                             , insertStandardImport
                             , insertThirdPartyImports
                             , runCodeGen
+                            , spreadModulePaths
                             , stringLiteral
                             , toAttributeName
                             , toClassName
@@ -840,6 +841,13 @@ compileModule pythonVersion' source =
             , ((3, 5), require "typing" "typing" $ standardImports context)
             ]
 
+spreadModulePaths :: [ModulePath] -> [Code]
+spreadModulePaths modulePaths = pathsToPackageNames $ map ancestors modulePaths
+  where
+    pathsToPackageNames :: [S.Set ModulePath] -> [Code]
+    pathsToPackageNames modulePaths' = S.toAscList $ S.map toImportPath $
+        S.unions modulePaths'
+
 compilePackageMetadata :: Package' -> InstallRequires -> Code
 compilePackageMetadata package@Package { metadata = metadata' }
                        (InstallRequires deps optDeps) =
@@ -919,7 +927,7 @@ setup(
                             | Author { email = Just e } <- authors metadata'
                             ]
     pPackages :: Code
-    pPackages = strings $ map toImportPath $ MS.keys $ modules package
+    pPackages = strings $ spreadModulePaths $ MS.keys $ modules package
     pInstallRequires :: Code
     pInstallRequires = strings $ S.toList deps
     pPolyfillRequires :: Code
diff --git a/test/Nirum/Targets/PythonSpec.hs b/test/Nirum/Targets/PythonSpec.hs
index 4a28b64..6f1d129 100644
--- a/test/Nirum/Targets/PythonSpec.hs
+++ b/test/Nirum/Targets/PythonSpec.hs
@@ -36,11 +36,12 @@ import Nirum.Constructs.TypeExpression ( TypeExpression ( ListModifier
                                                         , TypeIdentifier
                                                         )
                                        )
-import Nirum.Package (Package, resolveBoundModule)
+import Nirum.Package (Package(modules), resolveBoundModule)
 import Nirum.Package.Metadata ( Author (Author, email, name, uri)
                               , Metadata (Metadata, authors, target, version)
                               , Target (compilePackage)
                               )
+import qualified Nirum.Package.ModuleSet as MS
 import Nirum.PackageSpec (createPackage)
 import qualified Nirum.Targets.Python as PY
 import Nirum.Targets.Python ( Source (Source)
@@ -349,6 +350,15 @@ spec = parallel $ forM_ versions $ \ (ver, typing) -> do
                                              (3, 4) "ipaddress"
             (req4 `unionInstallRequires` req5) `shouldBe` req6
             (req5 `unionInstallRequires` req4) `shouldBe` req6
+    describe "Add ancestors of packages" $ do
+        let (Source pkg _) = makeDummySource $ Module [] Nothing
+            modulePaths = MS.keys $ modules pkg
+        specify "spreadModulePaths" $
+            PY.spreadModulePaths modulePaths `shouldBe` [ "foo"
+                                                        , "foo.bar"
+                                                        , "qux"
+                                                        ]
+
 
 {-# ANN module ("HLint: ignore Functor law" :: String) #-}
 {-# ANN module ("HLint: ignore Monad law, left identity" :: String) #-}