diff --git a/Makefile b/Makefile
index 10174e1072fabb4f648b4efcaaaf3a1e38a822a1..313737d9d8e4c123934e7993eb1803974e847698 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,5 @@
 LP = lambdapi
-LP_SRC != find . -type f -name "*.lp"
+LP_SRC  != find encodings prelude -type f -name "*.lp"
 LP_OBJ = ${LP_SRC:S/.lp$/.lpo/}
 
 .SUFFIXES: .lpo .lp