diff --git a/src/witness/yamlWitness.ml b/src/witness/yamlWitness.ml
index 1f83c8625e..1f106c936e 100644
--- a/src/witness/yamlWitness.ml
+++ b/src/witness/yamlWitness.ml
@@ -246,9 +246,7 @@ struct
       if entry_type_enabled YamlWitnessType.LocationInvariant.entry_type then (
         LH.fold (fun loc ns acc ->
             if List.exists is_invariant_node ns then (
-              let fundec = ref None in
               let inv = List.fold_left (fun acc n ->
-                  fundec := Some (Node.find_fundec n); (* TODO: fix location hack *)
                   let local = try NH.find (Lazy.force nh) n with Not_found -> Spec.D.bot () in
                   let lvals = local_lvals n local in
                   Invariant.(acc || R.ask_local_node n ~local (Invariant {Invariant.default_context with lvals})) [@coverage off] (* bisect_ppx cannot handle redefined (||) *)
@@ -256,10 +254,11 @@ struct
               in
               match inv with
               | `Lifted inv ->
+                let fundec = Node.find_fundec (List.hd ns) in (* TODO: fix location hack *)
+                let location_function = fundec.svar.vname in
+                let location = Entry.location ~location:loc ~location_function in
                 let invs = WitnessUtil.InvariantExp.process_exp inv in
                 List.fold_left (fun acc inv ->
-                    let location_function = (Option.get !fundec).svar.vname in
-                    let location = Entry.location ~location:loc ~location_function in
                     let invariant = Entry.invariant (CilType.Exp.show inv) in
                     let entry = Entry.location_invariant ~task ~location ~invariant in
                     entry :: acc
@@ -280,19 +279,18 @@ struct
       if entry_type_enabled YamlWitnessType.LoopInvariant.entry_type then (
         LH.fold (fun loc ns acc ->
             if WitnessInvariant.emit_loop_head && List.exists (WitnessUtil.NH.mem WitnessInvariant.loop_heads) ns then (
-              let fundec = ref None in
               let inv = List.fold_left (fun acc n ->
-                  fundec := Some (Node.find_fundec n); (* TODO: fix location hack *)
                   let local = try NH.find (Lazy.force nh) n with Not_found -> Spec.D.bot () in
                   Invariant.(acc || R.ask_local_node n ~local (Invariant Invariant.default_context)) [@coverage off] (* bisect_ppx cannot handle redefined (||) *)
                 ) (Invariant.bot ()) ns
               in
               match inv with
               | `Lifted inv ->
+                let fundec = Node.find_fundec (List.hd ns) in (* TODO: fix location hack *)
+                let location_function = fundec.svar.vname in
+                let location = Entry.location ~location:loc ~location_function in
                 let invs = WitnessUtil.InvariantExp.process_exp inv in
                 List.fold_left (fun acc inv ->
-                    let location_function = (Option.get !fundec).svar.vname in
-                    let location = Entry.location ~location:loc ~location_function in
                     let invariant = Entry.invariant (CilType.Exp.show inv) in
                     let entry = Entry.loop_invariant ~task ~location ~invariant in
                     entry :: acc
@@ -443,9 +441,7 @@ struct
           if invariant_type_enabled YamlWitnessType.InvariantSet.LocationInvariant.invariant_type then (
             LH.fold (fun loc ns acc ->
                 if List.exists is_invariant_node ns then (
-                  let fundec = ref None in
                   let inv = List.fold_left (fun acc n ->
-                      fundec := Some (Node.find_fundec n); (* TODO: fix location hack *)
                       let local = try NH.find (Lazy.force nh) n with Not_found -> Spec.D.bot () in
                       let lvals = local_lvals n local in
                       Invariant.(acc || R.ask_local_node n ~local (Invariant {Invariant.default_context with lvals})) [@coverage off] (* bisect_ppx cannot handle redefined (||) *)
@@ -453,10 +449,11 @@ struct
                   in
                   match inv with
                   | `Lifted inv ->
+                    let fundec = Node.find_fundec (List.hd ns) in (* TODO: fix location hack *)
+                    let location_function = fundec.svar.vname in
+                    let location = Entry.location ~location:loc ~location_function in
                     let invs = WitnessUtil.InvariantExp.process_exp inv in
                     List.fold_left (fun acc inv ->
-                        let location_function = (Option.get !fundec).svar.vname in
-                        let location = Entry.location ~location:loc ~location_function in
                         let invariant = CilType.Exp.show inv in
                         let invariant = Entry.location_invariant' ~location ~invariant in
                         invariant :: acc
@@ -477,19 +474,18 @@ struct
           if invariant_type_enabled YamlWitnessType.InvariantSet.LoopInvariant.invariant_type then (
             LH.fold (fun loc ns acc ->
                 if WitnessInvariant.emit_loop_head && List.exists (WitnessUtil.NH.mem WitnessInvariant.loop_heads) ns then (
-                  let fundec = ref None in
                   let inv = List.fold_left (fun acc n ->
-                      fundec := Some (Node.find_fundec n); (* TODO: fix location hack *)
                       let local = try NH.find (Lazy.force nh) n with Not_found -> Spec.D.bot () in
                       Invariant.(acc || R.ask_local_node n ~local (Invariant Invariant.default_context)) [@coverage off] (* bisect_ppx cannot handle redefined (||) *)
                     ) (Invariant.bot ()) ns
                   in
                   match inv with
                   | `Lifted inv ->
+                    let fundec = Node.find_fundec (List.hd ns) in (* TODO: fix location hack *)
+                    let location_function = fundec.svar.vname in
+                    let location = Entry.location ~location:loc ~location_function in
                     let invs = WitnessUtil.InvariantExp.process_exp inv in
                     List.fold_left (fun acc inv ->
-                        let location_function = (Option.get !fundec).svar.vname in
-                        let location = Entry.location ~location:loc ~location_function in
                         let invariant = CilType.Exp.show inv in
                         let invariant = Entry.loop_invariant' ~location ~invariant in
                         invariant :: acc