Manually remove $(BUILT_SOURCES) since no-dist-built-sources doesnt work
diff --git a/lib/swift/Makefile.am b/lib/swift/Makefile.am
index 6a6644a..ac61716 100644
--- a/lib/swift/Makefile.am
+++ b/lib/swift/Makefile.am
@@ -35,6 +35,9 @@
 check-local:
 	swift test
 
+distdir:
+	$(MAKE) $(AM_MAKEFLAGS) distdir-am
+
 EXTRA_DIST = \
 	Package.swift \
 	Sources \