1 files changed, 4 insertions, 2 deletions
diff --git a/src/checker_set.rs b/src/checker_set.rs
index 1a89631..83d97a1 100644
--- a/src/checker_set.rs
+++ b/src/checker_set.rs
@@ -103,13 +103,15 @@ impl CheckerState {
             }
             Element::Var(v) => {
                 let lookup = self.lookup_element(&v)?;
+                let container = self.check_set(&lookup.container)?; // TODO: necessary why?
+
                 // we have previously done the work to discover the type of
                 // this element, so what we're claiming now must match!
-                if !self.equal(set, &lookup.container) {
+                if !self.equal(set, &container) {
                     return Err(CheckerError::WrongSetForElement {
                         value: element.clone().into(),
                         claimed: set.clone(),
-                        real: lookup.container.clone(),
+                        real: container,
                     });
                 }
                 // If we found a formal binding, we have no value to report.