diff --git a/MANIFEST.in b/MANIFEST.in
index cdefbe6..d4be7a0 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -1,2 +1,3 @@
 recursive-include src *.h
+recursive-include dukpy/jscore *.js
 recursive-include dukpy/jsmodules *.js
diff --git a/setup.py b/setup.py
index abdd4bf..4c842c7 100755
--- a/setup.py
+++ b/setup.py
@@ -38,7 +38,7 @@ setup(
     ext_modules=[duktape],
     install_requires=INSTALL_REQUIRES,
     package_data={
-        'dukpy': ['jsmodules/*.js', 'jsmodules/react/*.js',
+        'dukpy': ['jscore/*.js', 'jsmodules/*.js', 'jsmodules/react/*.js',
                   'jsmodules/less/*/*.js', 'jsmodules/less/*/*/*.js'],
     },
     classifiers=[