diff --git a/.gitignore b/.gitignore
index e0463700152..f6c496091fc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -30,3 +30,4 @@ doc/source/_static/random.js
 doc/release/_release_notes_for_docs.txt
 doc/gh-pages
 wheels
+skimage/morphology/_skeletonize_3d_cy.pyx
diff --git a/MANIFEST.in b/MANIFEST.in
index 1a059991bf9..553b55d86f1 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -3,7 +3,7 @@ include setup*.py
 include MANIFEST.in
 include *.txt
 include Makefile
-recursive-include skimage *.pyx *.pxd *.pxi *.py *.c *.h *.ini *.md5 *.npy *.txt
+recursive-include skimage *.pyx *.pxd *.pxi *.py *.c *.h *.ini *.md5 *.npy *.txt *.in
 recursive-include skimage/data *
 
 include doc/Makefile