diff --git a/noir-projects/aztec-nr/aztec/src/state_vars/shared_immutable.nr b/noir-projects/aztec-nr/aztec/src/state_vars/shared_immutable.nr
index 341c83681c1b..29242863c9bd 100644
--- a/noir-projects/aztec-nr/aztec/src/state_vars/shared_immutable.nr
+++ b/noir-projects/aztec-nr/aztec/src/state_vars/shared_immutable.nr
@@ -1,9 +1,9 @@
-use crate::context::{Context};
-use crate::oracle::{storage::{storage_read, storage_write}};
-use crate::history::public_value_inclusion::prove_public_value_inclusion;
-use dep::std::option::Option;
-use dep::protocol_types::traits::{Deserialize, Serialize};
-use crate::state_vars::storage::Storage;
+use crate::{
+    context::{Context}, hash::pedersen_hash,
+    history::public_value_inclusion::prove_public_value_inclusion,
+    oracle::{storage::{storage_read, storage_write}}, state_vars::storage::Storage
+};
+use dep::protocol_types::{constants::GENERATOR_INDEX__IMMUTABLE_INITIALIZE_PLACEHOLDER, traits::{Deserialize, Serialize}};
 
 struct SharedImmutable<T>{
     context: Context,
@@ -18,9 +18,7 @@ impl<T> SharedImmutable<T> {
         context: Context,
         storage_slot: Field
     ) -> Self {
-        assert(
-            (storage_slot != 0) & (storage_slot != 1), "Storage slots 0 and 1 not allowed. Storage slots must start from 2."
-        );
+        assert(storage_slot != 0, "Storage slot 0 not allowed. Storage slots must start from 1.");
         Self { context, storage_slot }
     }
 
@@ -32,9 +30,12 @@ impl<T> SharedImmutable<T> {
         self.context.public.unwrap_unchecked().assert_deployment();
 
         // We check that the struct is not yet initialized by checking if the placeholder slot is 0
-        let placeholder_storage_slot = self.storage_slot - 1;
+        let placeholder_storage_slot = pedersen_hash(
+            [self.storage_slot],
+            GENERATOR_INDEX__IMMUTABLE_INITIALIZE_PLACEHOLDER
+        );
         let fields_read: [Field; 1] = storage_read(placeholder_storage_slot);
-        assert(fields_read[0] != 0, "SharedImmutable already initialized");
+        assert(fields_read[0] == 0, "SharedImmutable already initialized");
 
         // We populate the placeholder slot with a non-zero value to indicate that the struct is initialized
         storage_write(placeholder_storage_slot, [0xdead]);
diff --git a/noir-projects/noir-protocol-circuits/src/crates/types/src/constants.nr b/noir-projects/noir-protocol-circuits/src/crates/types/src/constants.nr
index be81885d0591..99b7f0068339 100644
--- a/noir-projects/noir-protocol-circuits/src/crates/types/src/constants.nr
+++ b/noir-projects/noir-protocol-circuits/src/crates/types/src/constants.nr
@@ -230,3 +230,4 @@ global GENERATOR_INDEX__VK = 41;
 global GENERATOR_INDEX__PRIVATE_CIRCUIT_PUBLIC_INPUTS = 42;
 global GENERATOR_INDEX__PUBLIC_CIRCUIT_PUBLIC_INPUTS = 43;
 global GENERATOR_INDEX__FUNCTION_ARGS = 44;
+global GENERATOR_INDEX__IMMUTABLE_INITIALIZE_PLACEHOLDER = 45;
diff --git a/yarn-project/circuits.js/src/constants.gen.ts b/yarn-project/circuits.js/src/constants.gen.ts
index 47bbff17361c..bfb3ef3f4626 100644
--- a/yarn-project/circuits.js/src/constants.gen.ts
+++ b/yarn-project/circuits.js/src/constants.gen.ts
@@ -144,4 +144,5 @@ export enum GeneratorIndex {
   PRIVATE_CIRCUIT_PUBLIC_INPUTS = 42,
   PUBLIC_CIRCUIT_PUBLIC_INPUTS = 43,
   FUNCTION_ARGS = 44,
+  IMMUTABLE_INITIALIZE_PLACEHOLDER = 45,
 }