diff --git a/src/lib_scoru_wasm/constants.ml b/src/lib_scoru_wasm/constants.ml
index a4c28f9f9f297d331edd4e264420222e4d75fce7..5e5a3d356e2a367b8ca11e28cf39f51abd662b2a 100644
--- a/src/lib_scoru_wasm/constants.ml
+++ b/src/lib_scoru_wasm/constants.ml
@@ -54,6 +54,9 @@ let kernel_fallback_key = Durable.key_of_string_exn "/readonly/kernel/boot.wasm"
 
 let stuck_flag_key = Durable.key_of_string_exn "/readonly/kernel/env/stuck"
 
+let upgrade_error_flag_key =
+  Durable.key_of_string_exn "/readonly/kernel/env/upgrade_error"
+
 let too_many_reboot_flag_key =
   Durable.key_of_string_exn "/readonly/kernel/env/too_many_reboot"
 
diff --git a/src/lib_scoru_wasm/fast/exec.ml b/src/lib_scoru_wasm/fast/exec.ml
index bd1d39f94efa8afcd33c7a7f1a9b7b46db94df9c..352d6cf3ea02a59ecd05fc19898d9865cdaffbf0 100644
--- a/src/lib_scoru_wasm/fast/exec.ml
+++ b/src/lib_scoru_wasm/fast/exec.ml
@@ -28,6 +28,8 @@ open Tezos_scoru_wasm
 module Wasmer = Tezos_wasmer
 module Lazy_containers = Tezos_lazy_containers
 
+include (Wasm_vm : Wasm_vm_sig.S)
+
 let store =
   Lazy.from_fun @@ fun () ->
   let engine = Wasmer.Engine.create Wasmer.Config.{compiler = SINGLEPASS} in
@@ -73,7 +75,8 @@ let compute builtins durable buffers =
 
   Wasmer.Instance.delete instance ;
 
+  let* durable = Wasm_vm.patch_flags_on_eval_successful host_state.durable in
   (* TODO: #4283
      The module is cached, but the cash is never cleaned.
      This is the point where it was scrubed before.*)
-  Lwt.return host_state.durable
+  Lwt.return durable
diff --git a/src/lib_scoru_wasm/test/helpers/wasm_utils.ml b/src/lib_scoru_wasm/test/helpers/wasm_utils.ml
index 0cf85bb3adf31c8236437b35fb65d572fc595751..2c2ff782dd7ae14ed3e7aaf4c217f01afbe9b795 100644
--- a/src/lib_scoru_wasm/test/helpers/wasm_utils.ml
+++ b/src/lib_scoru_wasm/test/helpers/wasm_utils.ml
@@ -237,8 +237,20 @@ let check_error ?expected_kind ?expected_reason error =
   match (expected_kind, error) with
   | Some `Decode, Wasm_pvm_errors.Decode_error {explanation; _} ->
       check_reason explanation
+  | ( Some `No_fallback_decode,
+      Wasm_pvm_errors.No_fallback_kernel
+        (Wasm_pvm_errors.Decode_cause {explanation; _}) ) ->
+      check_reason explanation
   | Some `Init, Init_error {explanation; _} -> check_reason explanation
+  | ( Some `No_fallback_init,
+      Wasm_pvm_errors.No_fallback_kernel
+        (Wasm_pvm_errors.Init_cause {explanation; _}) ) ->
+      check_reason explanation
   | Some `Link, Link_error explanation -> check_reason (Some explanation)
+  | ( Some `No_fallback_link,
+      Wasm_pvm_errors.No_fallback_kernel
+        (Wasm_pvm_errors.Link_cause explanation) ) ->
+      check_reason (Some explanation)
   | Some `Eval, Eval_error {explanation; _} -> check_reason explanation
   | Some `Invalid_state, Invalid_state explanation ->
       check_reason (Some explanation)
diff --git a/src/lib_scoru_wasm/test/test_init.ml b/src/lib_scoru_wasm/test/test_init.ml
index 465decf663260709086afb26d3a820d7d164b574..cf3c4593be42cbdf49f1c8490ea42678e750115e 100644
--- a/src/lib_scoru_wasm/test/test_init.ml
+++ b/src/lib_scoru_wasm/test/test_init.ml
@@ -38,7 +38,7 @@ let test_memory0_export () =
   let* stuck, _ = eval_until_stuck bad_module_tree in
   assert (
     check_error
-      ~expected_kind:`Init
+      ~expected_kind:`No_fallback_init
       ~expected_reason:"Module must export memory 0"
       stuck) ;
 
@@ -92,7 +92,7 @@ let test_module_name_size () =
   let* stuck, _ = eval_until_stuck bad_module_tree in
   assert (
     check_error
-      ~expected_kind:`Decode
+      ~expected_kind:`No_fallback_decode
       ~expected_reason:"Names cannot exceed 512 bytes"
       stuck) ;
   let*! good_module_tree = initial_tree (build_module 512) in
@@ -136,6 +136,12 @@ let test_imports () =
         ~module_name:bad_module_name
         ~item_name:bad_item_name
     in
+    let expected_error =
+      match expected_error with
+      | Wasm_pvm_errors.(Link_error e) ->
+          Wasm_pvm_errors.(No_fallback_kernel (Link_cause e))
+      | _ -> assert false
+    in
     if stuck = expected_error then return_unit
     else failwith "Unexpected stuck state!"
   in
@@ -153,6 +159,12 @@ let test_imports () =
         ~module_name:good_module_name
         ~item_name:bad_item_name
     in
+    let expected_error =
+      match expected_error with
+      | Wasm_pvm_errors.(Link_error e) ->
+          Wasm_pvm_errors.(No_fallback_kernel (Link_cause e))
+      | _ -> assert false
+    in
     if stuck = expected_error then return_unit
     else failwith "Unexpected stuck state!"
   in
@@ -192,7 +204,7 @@ let test_host_func_start_restriction () =
   let+ stuck, _ = eval_until_stuck state in
   assert (
     check_error
-      ~expected_kind:`Init
+      ~expected_kind:`No_fallback_init
       ~expected_reason:
         "host functions must not access memory during initialisation"
       stuck)
@@ -274,7 +286,7 @@ let test_float32_type () =
   Format.printf "%a\n%!" pp_state (Stuck stuck) ;
   assert (
     check_error
-      ~expected_kind:`Decode
+      ~expected_kind:`No_fallback_decode
       ~expected_reason:"float instructions are forbidden"
       stuck)
 
@@ -299,7 +311,7 @@ let test_float64_type () =
   Format.printf "%a\n%!" pp_state (Stuck stuck) ;
   assert (
     check_error
-      ~expected_kind:`Decode
+      ~expected_kind:`No_fallback_decode
       ~expected_reason:"float instructions are forbidden"
       stuck)
 
@@ -325,7 +337,7 @@ let test_float_value () =
   Format.printf "%a\n%!" pp_state (Stuck stuck) ;
   assert (
     check_error
-      ~expected_kind:`Decode
+      ~expected_kind:`No_fallback_decode
       ~expected_reason:"float instructions are forbidden"
       stuck)
 
diff --git a/src/lib_scoru_wasm/test/test_wasm_pvm.ml b/src/lib_scoru_wasm/test/test_wasm_pvm.ml
index 3d76e0ed8bc07e19fadca30dd8d416281d6f8c0b..d041564a45e5852d94823f61dce65e31c7ca49e1 100644
--- a/src/lib_scoru_wasm/test/test_wasm_pvm.ml
+++ b/src/lib_scoru_wasm/test/test_wasm_pvm.ml
@@ -794,7 +794,7 @@ let test_unkown_host_function_truncated () =
   (* The final reason for being stuck should be truncated after
      [Wasm_pvm_errors.messages_maximum_size]. *)
   let reason = String.sub reason 0 Wasm_pvm_errors.messages_maximum_size in
-  assert (is_stuck ~step:`Link ~reason state) ;
+  assert (is_stuck ~step:`No_fallback_link ~reason state) ;
   return_unit
 
 let test_bulk_noops () =
@@ -1073,8 +1073,7 @@ let test_reveal_upgrade_kernel_ok () =
   let*! () = assert_fallback_kernel tree @@ Some preimage in
   return_unit
 
-let test_reveal_upgrade_kernel_fallsback_on_error ~binary ~error invalid_kernel
-    () =
+let test_reveal_upgrade_kernel_fallsback_on_error ~binary invalid_kernel () =
   let open Lwt_result_syntax in
   let*! modul = wat2wasm @@ reveal_upgrade_kernel () in
   (* Let's first init the tree to compute. *)
@@ -1087,65 +1086,71 @@ let test_reveal_upgrade_kernel_fallsback_on_error ~binary ~error invalid_kernel
   (* At this point, the kernel should be installed, but not as fallback *)
   let*! () = assert_kernel tree @@ Some modul in
   let*! () = assert_fallback_kernel tree None in
-  (* Run the kernel, it should request a preimage reveal *)
-  let*! tree = set_empty_inbox_step 0l tree in
-  let*! tree = eval_until_input_requested tree in
-  (* At this point, the kernel should be installed, including as fallback *)
-  let*! () = assert_kernel tree @@ Some modul in
-  let*! () = assert_fallback_kernel tree @@ Some modul in
-  (* Check that reveal is requested *)
-  let*! state_after_first_message =
-    Wasm.Internal_for_tests.get_tick_state tree
-  in
-  assert (not @@ is_stuck state_after_first_message) ;
-  let*! info = Wasm.get_info tree in
-  let* () =
-    let open Wasm_pvm_state in
-    match info.Wasm_pvm_state.input_request with
-    | Wasm_pvm_state.Reveal_required (Reveal_raw_data hash) ->
-        (* The PVM has reached a point where it’s asking for some
-           preimage. Since the memory is left blank, we are looking
-           for the zero hash *)
-        let zero_hash = String.make 33 '\000' in
-        assert (hash = zero_hash) ;
-        return_unit
-    | No_input_required | Input_required | Reveal_required _ -> assert false
-  in
   let*! preimage =
     if binary then Lwt.return invalid_kernel else wat2wasm invalid_kernel
   in
-  let*! tree = Wasm.reveal_step (Bytes.of_string preimage) tree in
-  let*! tree = eval_until_input_requested tree in
-  let*! state_after_reveal = Wasm.Internal_for_tests.get_tick_state tree in
-  assert (not @@ is_stuck state_after_reveal) ;
-  (* At this point, the new_kernel should be installed, the old as fallback *)
-  let*! () = assert_kernel tree @@ Some preimage in
-  let*! () = assert_fallback_kernel tree @@ Some modul in
-  (* run until proper input requested *)
-  let*! tree = eval_until_input_requested tree in
-  let*! state_after_reveal = Wasm.Internal_for_tests.get_tick_state tree in
-  assert (not @@ is_stuck state_after_reveal) ;
-  (* At this point, the new_kernel should be installed, including as fallback *)
-  let*! () = assert_kernel tree @@ Some preimage in
-  let*! () = assert_fallback_kernel tree @@ Some modul in
+  (* Run the kernel, it should request a preimage reveal *)
+  let run_installer tree level =
+    let*! tree = set_empty_inbox_step level tree in
+    let*! tree = eval_until_input_requested tree in
+    (* At this point, the kernel should be installed, including as fallback *)
+    let*! () = assert_kernel tree @@ Some modul in
+    let*! () = assert_fallback_kernel tree @@ Some modul in
+    (* Check that reveal is requested *)
+    let*! state_after_first_message =
+      Wasm.Internal_for_tests.get_tick_state tree
+    in
+    assert (not @@ is_stuck state_after_first_message) ;
+    let*! info = Wasm.get_info tree in
+    let* () =
+      let open Wasm_pvm_state in
+      match info.Wasm_pvm_state.input_request with
+      | Wasm_pvm_state.Reveal_required (Reveal_raw_data hash) ->
+          (* The PVM has reached a point where it’s asking for some
+             preimage. Since the memory is left blank, we are looking
+             for the zero hash *)
+          let zero_hash = String.make 33 '\000' in
+          assert (hash = zero_hash) ;
+          return_unit
+      | No_input_required | Input_required | Reveal_required _ -> assert false
+    in
+    let*! tree = Wasm.reveal_step (Bytes.of_string preimage) tree in
+    let*! state_after_reveal = Wasm.Internal_for_tests.get_tick_state tree in
+    assert (not @@ is_stuck state_after_reveal) ;
+    let*! tree = eval_until_input_requested tree in
+    let*! state_after_reveal = Wasm.Internal_for_tests.get_tick_state tree in
+    assert (not @@ is_stuck state_after_reveal) ;
+    (* At this point, the new_kernel should be installed, including as fallback *)
+    let*! () = assert_kernel tree @@ Some preimage in
+    let*! () = assert_fallback_kernel tree @@ Some modul in
+    Lwt.return_ok tree
+  in
+  let* tree = run_installer tree 0l in
   (* run with new input, this should be the new kernel *)
   let*! tree = set_empty_inbox_step 2l tree in
   let*! tree = eval_until_input_requested tree in
   let*! state_after_second_message =
     Wasm.Internal_for_tests.get_tick_state tree
   in
-  (* The pvm should be temporarily stuck *)
-  assert (is_stuck ~step:error state_after_second_message) ;
-  (* The kernel is set to the invalid one *)
-  let*! () = assert_kernel tree @@ Some preimage in
-  let*! () = assert_fallback_kernel tree @@ Some modul in
-  (* Running the kernel one more tick should result in fallback *)
-  let*! tree = Wasm.compute_step tree in
-  let*! post_stuck_state = Wasm.Internal_for_tests.get_tick_state tree in
-  assert (not @@ is_stuck post_stuck_state) ;
-  (* The kernel is set to the invalid one *)
+  let has_upgrade_error_flag tree =
+    let*! durable = wrap_as_durable_storage tree in
+    let durable = Durable.of_storage_exn durable in
+    let*! found_error =
+      Durable.find_value durable Constants.upgrade_error_flag_key
+    in
+    Lwt.return_ok @@ Option.is_some found_error
+  in
+  (* The pvm should have an upgrade error, but not be stuck *)
+  assert (not @@ is_stuck state_after_second_message) ;
+  let* has_upgrade_error = has_upgrade_error_flag tree in
+  assert has_upgrade_error ;
+  (* The kernel is set to the fallback one *)
   let*! () = assert_kernel tree @@ Some modul in
   let*! () = assert_fallback_kernel tree @@ Some modul in
+  (* The next evaluation should delete the upgrade error. *)
+  let* tree = run_installer tree 3l in
+  let* has_upgrade_error = has_upgrade_error_flag tree in
+  assert (not has_upgrade_error) ;
   return_unit
 
 let test_kernel_reboot_gen ~reboots ~expected_reboots ~pvm_max_reboots =
@@ -1637,14 +1642,12 @@ let tests =
       `Quick
       (test_reveal_upgrade_kernel_fallsback_on_error
          ~binary:true
-         ~error:`Decode
          "INVALID WASM!!!");
     tztest
       "Test kernel upgrade fallsback on linking error"
       `Quick
       (test_reveal_upgrade_kernel_fallsback_on_error
          ~binary:false
-         ~error:`Link
          {|
 (module
  (import "invalid_module" "write_debug"
@@ -1655,7 +1658,6 @@ let tests =
       `Quick
       (test_reveal_upgrade_kernel_fallsback_on_error
          ~binary:false
-         ~error:`Init
          "(module (memory 1))");
     tztest
       "Test scheduling with 10 inputs in a unique inbox"
diff --git a/src/lib_scoru_wasm/wasm_vm.ml b/src/lib_scoru_wasm/wasm_vm.ml
index b173d04c89eeec664340f3d8fd5d5b7a69a1bebe..bb97ee53478244d5c751f24ef0d3bb668f4e9de4 100644
--- a/src/lib_scoru_wasm/wasm_vm.ml
+++ b/src/lib_scoru_wasm/wasm_vm.ml
@@ -58,6 +58,29 @@ let has_stuck_flag durable =
   let+ stuck = Durable.(find_value durable Constants.stuck_flag_key) in
   Option.is_some stuck
 
+let has_upgrade_error_flag durable =
+  let open Lwt_syntax in
+  let+ error = Durable.(find_value durable Constants.upgrade_error_flag_key) in
+  Option.is_some error
+
+let patch_flags_on_eval_successful durable =
+  let open Lwt_syntax in
+  (* We have an empty set of admin instructions, but need to wait until we can restart *)
+  let* has_stuck_flag = has_stuck_flag durable in
+  let* durable =
+    if has_stuck_flag then
+      Durable.(delete ~edit_readonly:true durable Constants.stuck_flag_key)
+    else Lwt.return durable
+  in
+  let* has_upgrade_error_flag = has_upgrade_error_flag durable in
+  let+ durable =
+    if has_upgrade_error_flag then
+      Durable.(
+        delete ~edit_readonly:true durable Constants.upgrade_error_flag_key)
+    else Lwt.return durable
+  in
+  durable
+
 let mark_for_reboot {reboot_counter; durable; _} =
   let open Lwt_syntax in
   let+ has_reboot_flag = has_reboot_flag durable in
@@ -114,6 +137,14 @@ let unsafe_next_tick_state ({buffers; durable; tick_state; _} as pvm_state) =
             Constants.kernel_fallback_key
             Constants.kernel_key
         in
+        let* durable =
+          Durable.write_value_exn
+            ~edit_readonly:true
+            durable
+            Constants.upgrade_error_flag_key
+            0L
+            ""
+        in
         return ~durable Padding
       else return ~status:Failing (Stuck (No_fallback_kernel cause))
   | Stuck e -> return ~status:Failing (Stuck e)
@@ -248,11 +279,8 @@ let unsafe_next_tick_state ({buffers; durable; tick_state; _} as pvm_state) =
       return ~durable Padding
   | _ when eval_has_finished tick_state ->
       (* We have an empty set of admin instructions, but need to wait until we can restart *)
-      let* has_stuck_flag = has_stuck_flag durable in
-      if has_stuck_flag then
-        let* durable = Durable.(delete durable Constants.stuck_flag_key) in
-        return ~durable Padding
-      else return Padding
+      let* durable = patch_flags_on_eval_successful durable in
+      return ~durable Padding
   | Eval {config; module_reg} ->
       (* Continue execution. *)
       let store = Durable.to_storage durable in
@@ -386,6 +414,10 @@ let compute_step pvm_state =
 
 let input_request pvm_state =
   match pvm_state.tick_state with
+  | Stuck (Decode_error _ | Init_error _ | Link_error _) ->
+      (* These stuck states are recovered on the next tick by
+         the fallback mechanism. *)
+      Wasm_pvm_state.No_input_required
   | Stuck _ -> Wasm_pvm_state.Input_required
   | Snapshot -> Wasm_pvm_state.No_input_required
   | Collect -> Wasm_pvm_state.Input_required
@@ -396,7 +428,9 @@ let input_request pvm_state =
   | _ -> Wasm_pvm_state.No_input_required
 
 let is_top_level_padding pvm_state =
-  eval_has_finished pvm_state.tick_state && not (is_time_for_snapshot pvm_state)
+  match pvm_state.tick_state with
+  | Padding -> not @@ is_time_for_snapshot pvm_state
+  | _ -> false
 
 let measure_executed_ticks (transition : pvm_state -> pvm_state Lwt.t)
     (initial_state : pvm_state) : (pvm_state * int64) Lwt.t =
diff --git a/src/lib_scoru_wasm/wasm_vm.mli b/src/lib_scoru_wasm/wasm_vm.mli
index b06de110f95b546120f25ded4d8ca30c132b9f03..d5a482a2625715e8402b38b4797006c6f5374e56 100644
--- a/src/lib_scoru_wasm/wasm_vm.mli
+++ b/src/lib_scoru_wasm/wasm_vm.mli
@@ -49,6 +49,11 @@ val compute_step_many_until :
     finished successfully. *)
 val eval_has_finished : tick_state -> bool
 
+(** [patch_flags_on_eval_successful durable] clears flags set by
+    previous attempted runs of kernel_run. Once an evaluation has
+    succeeded, these can be safely deleted. *)
+val patch_flags_on_eval_successful : Durable.t -> Durable.t Lwt.t
+
 (** [should_compute pvm_state] probes whether it is possible to continue with
     more computational steps. *)
 val should_compute : pvm_state -> bool