Fix NF tracking error

1 files changed, 3 insertions, 2 deletions

diff --git a/dhall/src/normalize.rs b/dhall/src/normalize.rs
index 85cadca..dbb6d95 100644
--- a/dhall/src/normalize.rs
+++ b/dhall/src/normalize.rs
@@ -1060,8 +1060,9 @@ mod thunk {
                         e.clone(),
                     )
                 }
-                ThunkInternal::Value(m, v) => {
-                    ThunkInternal::Value(*m, v.subst_shift(var, val))
+                ThunkInternal::Value(_, v) => {
+                    // The resulting value may not stay in normal form after substitution
+                    ThunkInternal::Value(WHNF, v.subst_shift(var, val))
                 }
             }
         }