diff --git a/zapp/zapp.bzl b/zapp/zapp.bzl
index 5159faf..4c805c9 100644
--- a/zapp/zapp.bzl
+++ b/zapp/zapp.bzl
@@ -61,6 +61,8 @@ def _zapp_impl(ctx):
     # TODO: also handle ctx.attr.src.data_runfiles.symlinks
     srcs = [
         f for f in ctx.attr.src.default_runfiles.files.to_list()
+        # Strip out transitive sources from PyPi archives
+        if f.path.find("/pypi__") == -1
     ]
 
     # Find the list of directories to add to sys