diff --git a/examples/ZoKrates/pf/assert2.zok b/examples/ZoKrates/pf/assert2.zok
new file mode 100644
index 00000000..966c0916
--- /dev/null
+++ b/examples/ZoKrates/pf/assert2.zok
@@ -0,0 +1,3 @@
+def main(private field A, private field B) -> bool:
+  assert(A+B == 123)
+  return true
diff --git a/examples/ZoKrates/pf/assert2.zok.pin b/examples/ZoKrates/pf/assert2.zok.pin
new file mode 100644
index 00000000..cbb92e0a
--- /dev/null
+++ b/examples/ZoKrates/pf/assert2.zok.pin
@@ -0,0 +1,10 @@
+(set_default_modulus 52435875175126190479447740508185965837690552500527637822603658699938581184513
+
+(let (
+
+  (A #f4)
+  (B #f-4)
+
+) true ;ignored
+
+))
diff --git a/examples/ZoKrates/pf/assert2.zok.vin b/examples/ZoKrates/pf/assert2.zok.vin
new file mode 100644
index 00000000..04e3a61d
--- /dev/null
+++ b/examples/ZoKrates/pf/assert2.zok.vin
@@ -0,0 +1,9 @@
+(set_default_modulus 52435875175126190479447740508185965837690552500527637822603658699938581184513
+
+(let (
+
+  (return true)
+
+) true; ignored
+
+))
diff --git a/scripts/zokrates_test.zsh b/scripts/zokrates_test.zsh
index ebd3e1dc..b80a8517 100755
--- a/scripts/zokrates_test.zsh
+++ b/scripts/zokrates_test.zsh
@@ -90,6 +90,7 @@ pf_test_only_pf sha_temp2
 #pf_test_only_pf test_sha256
 
 pf_test assert
+pf_test assert2
 pf_test_isolate isolate_assert
 pf_test 3_plus
 pf_test xor
diff --git a/src/target/r1cs/bellman.rs b/src/target/r1cs/bellman.rs
index d8b8dbd6..e23e6c54 100644
--- a/src/target/r1cs/bellman.rs
+++ b/src/target/r1cs/bellman.rs
@@ -112,16 +112,17 @@ impl<'a, F: PrimeField> Circuit<F> for SynthInput<'a> {
                 "Bellman doesn't support rounds"
             );
             let public = matches!(var.ty(), VarType::Inst);
-            let name_f = || format!("{var:?}");
+            let name = self.0.r1cs.names.get(&var).unwrap();
+            let name_f = || format!("{name:?}");
             let val_f = || {
                 Ok({
                     let i_val = &values.as_ref().expect("missing values")[i];
                     let ff_val = int_to_ff(i_val.as_pf().into());
-                    debug!("value : {var:?} -> {ff_val:?} ({i_val})");
+                    debug!("value : {name:?} -> {ff_val:?} ({i_val})");
                     ff_val
                 })
             };
-            debug!("var: {:?}, public: {}", var, public);
+            debug!("var: {:?}, public: {}", name, public);
             let v = if public {
                 cs.alloc_input(name_f, val_f)?
             } else {
diff --git a/src/target/r1cs/opt.rs b/src/target/r1cs/opt.rs
index f48daed6..f5e335d4 100644
--- a/src/target/r1cs/opt.rs
+++ b/src/target/r1cs/opt.rs
@@ -133,15 +133,39 @@ impl LinReducer {
                             self.queue.push(use_id);
                         }
                     }
-                    self.r1cs.idx_to_sig.remove_fwd(&var);
-                    self.r1cs.terms.remove(&var);
+                    self.remove_var(var);
                     debug_assert_eq!(0, self.uses[&var].len());
                 }
             }
         }
         self.r1cs.constraints.retain(|c| !constantly_true(c));
+        self.remove_dead_variables();
         self.r1cs
     }
+
+    fn remove_var(&mut self, var: Var) {
+        self.r1cs.idx_to_sig.remove_fwd(&var);
+        self.r1cs.terms.remove(&var);
+    }
+
+    /// Remove any private dead variables. Run this at the end of optimization.
+    fn remove_dead_variables(&mut self) {
+        let used: HashSet<Var> = self
+            .r1cs
+            .constraints
+            .iter()
+            .flat_map(|c| {
+                c.0.monomials
+                    .keys()
+                    .chain(c.1.monomials.keys().chain(c.2.monomials.keys()))
+            })
+            .copied()
+            .collect();
+        let present: HashSet<Var> = self.r1cs.terms.keys().copied().collect();
+        for to_remove in present.difference(&used) {
+            self.remove_var(*to_remove);
+        }
+    }
 }
 
 fn as_linear_sub((a, b, c): &(Lc, Lc, Lc), r1cs: &R1cs) -> Option<(Var, Lc)> {