kc3-lang/kc3

diff --git a/libkc3/data.c b/libkc3/data.c
index b45c5c0..047746d 100644
--- a/libkc3/data.c
+++ b/libkc3/data.c
@@ -278,6 +278,10 @@ bool data_clean (const s_sym *type, void *data)
   if (type == &g_sym_Sym) {
     return true;
   }
+  if (type == &g_sym_Tag) {
+    tag_clean(data);
+    return true;
+  }
   if (type == &g_sym_Tuple) {
     tuple_clean(data);
     return true;
diff --git a/libkc3/sym.c b/libkc3/sym.c
index 666284b..642e748 100644
--- a/libkc3/sym.c
+++ b/libkc3/sym.c
@@ -515,6 +515,10 @@ bool sym_must_clean (const s_sym *sym, bool *must_clean)
     *must_clean = false;
     return true;
   }
+  if (sym == &g_sym_Cfn) {
+    *must_clean = true;
+    return true;
+  }
   if (sym == &g_sym_Character) {
     *must_clean = false;
     return true;