diff --git a/build.lua b/build.lua
index 1d54af6ed..2999f8527 100644
--- a/build.lua
+++ b/build.lua
@@ -5,7 +5,7 @@ module = "pgf"
 installfiles = {}
 sourcefiles = {}
 unpackfiles = {}
-tdsdirs = {tex = "tex"}
+tdsdirs = { tex = "tex", source = "source" }
 
 -- For the manual
 docfiledir = "./doc/generic/pgf"