diff --git a/crates/fidc-core/src/platform_expr_strategy.rs b/crates/fidc-core/src/platform_expr_strategy.rs
index b8f3ad6..2b3ff11 100644
--- a/crates/fidc-core/src/platform_expr_strategy.rs
+++ b/crates/fidc-core/src/platform_expr_strategy.rs
@@ -6129,7 +6129,7 @@ impl PlatformExprStrategy {
                 if Self::is_reserved_scope_name(identifier.as_str())
                     || self.prelude_declared_identifiers.contains(identifier)
                     || (!self.stock_extra_factor_identifiers.contains(identifier)
-                        && !item.extra_factors.contains_key(identifier)
+                        && !item.extra_factors.contains_key(identifier.as_str())
                         && !day.available_factor_names.contains(identifier)
                         && !day.available_text_factor_names.contains(identifier))
                 {
@@ -6140,7 +6140,7 @@ impl PlatformExprStrategy {
                 } else {
                     let value = item
                         .extra_factors
-                        .get(identifier)
+                        .get(identifier.as_str())
                         .copied()
                         .unwrap_or(f64::NAN);
                     scope.push_dynamic(identifier.clone(), Dynamic::from(value));