diff --git a/crates/optimism/chainspec/src/lib.rs b/crates/optimism/chainspec/src/lib.rs
index 82c530db9..e96403b57 100644
--- a/crates/optimism/chainspec/src/lib.rs
+++ b/crates/optimism/chainspec/src/lib.rs
@@ -159,6 +159,13 @@ impl OpChainSpecBuilder {
         self
     }
 
+    /// Enable Interop at genesis
+    pub fn interop_activated(mut self) -> Self {
+        self = self.isthmus_activated();
+        self.inner = self.inner.with_fork(OpHardfork::Interop, ForkCondition::Timestamp(0));
+        self
+    }
+
     /// Build the resulting [`OpChainSpec`].
     ///
     /// # Panics
@@ -329,6 +336,7 @@ impl From<Genesis> for OpChainSpec {
             (OpHardfork::Granite.boxed(), genesis_info.granite_time),
             (OpHardfork::Holocene.boxed(), genesis_info.holocene_time),
             (OpHardfork::Isthmus.boxed(), genesis_info.isthmus_time),
+            // (OpHardfork::Interop.boxed(), genesis_info.interop_time),
         ];
 
         let mut time_hardforks = time_hardfork_opts
@@ -982,6 +990,7 @@ mod tests {
             OpHardfork::Granite.boxed(),
             OpHardfork::Holocene.boxed(),
             // OpHardfork::Isthmus.boxed(),
+            // OpHardfork::Interop.boxed(),
         ];
 
         for (expected, actual) in expected_hardforks.iter().zip(hardforks.iter()) {
diff --git a/crates/optimism/evm/src/config.rs b/crates/optimism/evm/src/config.rs
index 6375ceb3c..3e380021c 100644
--- a/crates/optimism/evm/src/config.rs
+++ b/crates/optimism/evm/src/config.rs
@@ -17,6 +17,9 @@ pub fn revm_spec_by_timestamp_after_bedrock(
     chain_spec: impl OpHardforks,
     timestamp: u64,
 ) -> OpSpecId {
+    // if chain_spec.is_interop_active_at_timestamp(timestamp) {
+    //     OpSpecId::INTEROP
+    // } else
     if chain_spec.is_isthmus_active_at_timestamp(timestamp) {
         OpSpecId::ISTHMUS
     } else if chain_spec.is_holocene_active_at_timestamp(timestamp) {
@@ -49,6 +52,10 @@ mod tests {
             let cs = ChainSpecBuilder::mainnet().chain(reth_chainspec::Chain::from_id(10)).into();
             f(cs).build()
         }
+        // assert_eq!(
+        //     revm_spec_by_timestamp_after_bedrock(op_cs(|cs| cs.interop_activated()), 0),
+        //     OpSpecId::INTEROP
+        // );
         assert_eq!(
             revm_spec_by_timestamp_after_bedrock(op_cs(|cs| cs.isthmus_activated()), 0),
             OpSpecId::ISTHMUS
diff --git a/crates/optimism/hardforks/src/hardfork.rs b/crates/optimism/hardforks/src/hardfork.rs
index 313fd67dd..5afade450 100644
--- a/crates/optimism/hardforks/src/hardfork.rs
+++ b/crates/optimism/hardforks/src/hardfork.rs
@@ -35,6 +35,8 @@ hardfork!(
         Holocene,
         /// Isthmus: <https://github.com/ethereum-optimism/specs/blob/main/specs/protocol/isthmus/overview.md>
         Isthmus,
+        /// TODO: add interop hardfork overview when available
+        Interop,
     }
 );
 
@@ -162,6 +164,7 @@ impl OpHardfork {
                 Self::Granite => Some(1723478400),
                 Self::Holocene => Some(1732633200),
                 Self::Isthmus => todo!(),
+                Self::Interop => todo!(),
             },
         )
     }
@@ -198,6 +201,7 @@ impl OpHardfork {
                 Self::Granite => Some(1726070401),
                 Self::Holocene => Some(1736445601),
                 Self::Isthmus => todo!(),
+                Self::Interop => todo!(),
             },
         )
     }
@@ -378,8 +382,10 @@ mod tests {
 
     #[test]
     fn check_op_hardfork_from_str() {
-        let hardfork_str =
-            ["beDrOck", "rEgOlITH", "cAnYoN", "eCoToNe", "FJorD", "GRaNiTe", "hOlOcEnE", "isthMUS"];
+        let hardfork_str = [
+            "beDrOck", "rEgOlITH", "cAnYoN", "eCoToNe", "FJorD", "GRaNiTe", "hOlOcEnE", "isthMUS",
+            "inTerOP",
+        ];
         let expected_hardforks = [
             OpHardfork::Bedrock,
             OpHardfork::Regolith,
@@ -389,6 +395,7 @@ mod tests {
             OpHardfork::Granite,
             OpHardfork::Holocene,
             OpHardfork::Isthmus,
+            OpHardfork::Interop,
         ];
 
         let hardforks: Vec<OpHardfork> =
diff --git a/crates/optimism/hardforks/src/lib.rs b/crates/optimism/hardforks/src/lib.rs
index fbe77aa20..337911683 100644
--- a/crates/optimism/hardforks/src/lib.rs
+++ b/crates/optimism/hardforks/src/lib.rs
@@ -69,4 +69,10 @@ pub trait OpHardforks: EthereumHardforks {
     fn is_isthmus_active_at_timestamp(&self, timestamp: u64) -> bool {
         self.op_fork_activation(OpHardfork::Isthmus).active_at_timestamp(timestamp)
     }
+
+    /// Returns `true` if [`Interop`](OpHardfork::Interop) is active at given block
+    /// timestamp.
+    fn is_interop_active_at_timestamp(&self, timestamp: u64) -> bool {
+        self.op_fork_activation(OpHardfork::Interop).active_at_timestamp(timestamp)
+    }
 }
diff --git a/crates/optimism/payload/src/builder.rs b/crates/optimism/payload/src/builder.rs
index 34ff1f715..46bf3a55c 100644
--- a/crates/optimism/payload/src/builder.rs
+++ b/crates/optimism/payload/src/builder.rs
@@ -793,6 +793,11 @@ where
         self.chain_spec.is_isthmus_active_at_timestamp(self.attributes().timestamp())
     }
 
+    /// Returns true if interop is active for the payload.
+    pub fn is_interop_active(&self) -> bool {
+        self.chain_spec.is_interop_active_at_timestamp(self.attributes().timestamp())
+    }
+
     /// Returns true if the fees are higher than the previous payload.
     pub fn is_better_payload(&self, total_fees: U256) -> bool {
         is_better_payload(self.best_payload.as_ref(), total_fees)