diff --git a/prusti-contracts/prusti-specs/src/rewriter.rs b/prusti-contracts/prusti-specs/src/rewriter.rs
index ad72395e549..c580c9bcf4b 100644
--- a/prusti-contracts/prusti-specs/src/rewriter.rs
+++ b/prusti-contracts/prusti-specs/src/rewriter.rs
@@ -105,30 +105,21 @@ impl AstRewriter {
         // - `item_span` is set to `expr.span()` so that any errors reported
         //   for the spec item will be reported on the span of the expression
         //   written by the user
-        // - `((#expr) : bool)` syntax is used to report type errors in the
+        // - `let ...: bool = #expr` syntax is used to report type errors in the
         //   expression with the correct error message, i.e. that the expected
         //   type is `bool`, not that the expected *return* type is `bool`
-        // - `!!(...)` is used to fix an edge-case when the expression consists
-        //   of a single identifier; without the double negation, the `Return`
-        //   terminator in MIR has a span set to the one character just after
-        //   the identifier
-        let (return_type, return_modifier) = match &spec_type {
-            SpecItemType::Termination => (
-                quote_spanned! {item_span => Int},
-                quote_spanned! {item_span => Int::new(0) + },
-            ),
-            SpecItemType::Predicate(return_type) => (return_type.clone(), TokenStream::new()),
-            _ => (
-                quote_spanned! {item_span => bool},
-                quote_spanned! {item_span => !!},
-            ),
+        let return_type = match &spec_type {
+            SpecItemType::Termination => quote_spanned! {item_span => Int},
+            SpecItemType::Predicate(return_type) => return_type.clone(),
+            _ => quote_spanned! {item_span => bool},
         };
         let mut spec_item: syn::ItemFn = parse_quote_spanned! {item_span=>
             #[allow(unused_must_use, unused_parens, unused_variables, dead_code, non_snake_case)]
             #[prusti::spec_only]
             #[prusti::spec_id = #spec_id_str]
             fn #item_name() -> #return_type {
-                #return_modifier ((#expr) : #return_type)
+                let prusti_result: #return_type = #expr;
+                prusti_result
             }
         };
 
diff --git a/prusti-viper/src/encoder/mir/pure/interpreter/interpreter_high.rs b/prusti-viper/src/encoder/mir/pure/interpreter/interpreter_high.rs
index 44f37bc2bdd..fefc01e0b5f 100644
--- a/prusti-viper/src/encoder/mir/pure/interpreter/interpreter_high.rs
+++ b/prusti-viper/src/encoder/mir/pure/interpreter/interpreter_high.rs
@@ -1053,7 +1053,8 @@ impl<'p, 'v: 'p, 'tcx: 'v> BackwardMirInterpreter<'tcx>
             mir::StatementKind::StorageLive(..)
             | mir::StatementKind::StorageDead(..)
             | mir::StatementKind::FakeRead(..)
-            | mir::StatementKind::PlaceMention(..) => {
+            | mir::StatementKind::PlaceMention(..)
+            | mir::StatementKind::AscribeUserType(..) => {
                 // Nothing to do
             }
             mir::StatementKind::Assign(box (lhs, rhs)) => {