diff --git a/setup.py b/setup.py
index 98d482738..ebff9a17e 100755
--- a/setup.py
+++ b/setup.py
@@ -657,8 +657,8 @@ class pil_build_ext(build_ext):
 
         tk_libs = ['psapi'] if sys.platform == 'win32' else []
         exts.append(Extension("PIL._imagingtk",
-                              ["src/_imagingtk.c", "Tk/tkImaging.c"],
-                              include_dirs=['Tk'],
+                              ["src/_imagingtk.c", "src/Tk/tkImaging.c"],
+                              include_dirs=['src/Tk'],
                               libraries=tk_libs))
 
         exts.append(Extension("PIL._imagingmath", ["src/_imagingmath.c"]))
diff --git a/Tk/_tkmini.h b/src/Tk/_tkmini.h
similarity index 100%
rename from Tk/_tkmini.h
rename to src/Tk/_tkmini.h
diff --git a/Tk/tkImaging.c b/src/Tk/tkImaging.c
similarity index 100%
rename from Tk/tkImaging.c
rename to src/Tk/tkImaging.c