diff --git a/Cargo.lock b/Cargo.lock
index bd11682..5576e10 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -687,6 +687,7 @@ dependencies = [
  "regex",
  "revive-builtins",
  "revive-common",
+ "revive-extensions",
  "revive-linker",
  "revive-stdlib",
  "semver 1.0.22",
@@ -1349,7 +1350,7 @@ dependencies = [
 [[package]]
 name = "polkavm"
 version = "0.9.3"
-source = "git+https://github.com/koute/polkavm.git#4ca06cc1b7cb435b2b92e81e30c2eb0e988f563e"
+source = "git+https://github.com/koute/polkavm.git?branch=master_byteswap#8b8050bd58be30c6001925b5b2785bc9c98cca4e"
 dependencies = [
  "libc",
  "log",
@@ -1361,7 +1362,7 @@ dependencies = [
 [[package]]
 name = "polkavm-assembler"
 version = "0.9.0"
-source = "git+https://github.com/koute/polkavm.git#4ca06cc1b7cb435b2b92e81e30c2eb0e988f563e"
+source = "git+https://github.com/koute/polkavm.git?branch=master_byteswap#8b8050bd58be30c6001925b5b2785bc9c98cca4e"
 dependencies = [
  "log",
 ]
@@ -1369,7 +1370,7 @@ dependencies = [
 [[package]]
 name = "polkavm-common"
 version = "0.9.0"
-source = "git+https://github.com/koute/polkavm.git#4ca06cc1b7cb435b2b92e81e30c2eb0e988f563e"
+source = "git+https://github.com/koute/polkavm.git?branch=master_byteswap#8b8050bd58be30c6001925b5b2785bc9c98cca4e"
 dependencies = [
  "log",
 ]
@@ -1377,7 +1378,7 @@ dependencies = [
 [[package]]
 name = "polkavm-linker"
 version = "0.9.2"
-source = "git+https://github.com/koute/polkavm.git#4ca06cc1b7cb435b2b92e81e30c2eb0e988f563e"
+source = "git+https://github.com/koute/polkavm.git?branch=master_byteswap#8b8050bd58be30c6001925b5b2785bc9c98cca4e"
 dependencies = [
  "gimli",
  "hashbrown 0.14.3",
@@ -1391,7 +1392,7 @@ dependencies = [
 [[package]]
 name = "polkavm-linux-raw"
 version = "0.9.0"
-source = "git+https://github.com/koute/polkavm.git#4ca06cc1b7cb435b2b92e81e30c2eb0e988f563e"
+source = "git+https://github.com/koute/polkavm.git?branch=master_byteswap#8b8050bd58be30c6001925b5b2785bc9c98cca4e"
 
 [[package]]
 name = "ppv-lite86"
diff --git a/Cargo.toml b/Cargo.toml
index 902f9e2..9f3daae 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -27,9 +27,9 @@ path-slash = "0.2"
 rayon = "1.8"
 structopt = { version = "0.3", default-features = false }
 rand = "0.8"
-polkavm-common = { git = "https://github.com/koute/polkavm.git" } 
-polkavm-linker = { git = "https://github.com/koute/polkavm.git" } 
-polkavm = { git = "https://github.com/koute/polkavm.git" } 
+polkavm-common = { branch = "master_byteswap", git = "https://github.com/koute/polkavm.git" } 
+polkavm-linker = { branch = "master_byteswap", git = "https://github.com/koute/polkavm.git" } 
+polkavm = { branch = "master_byteswap", git = "https://github.com/koute/polkavm.git" } 
 alloy-primitives = "0.6"
 alloy-sol-types = "0.6"
 env_logger = { version = "0.10.0", default-features = false }
diff --git a/crates/extensions/build.rs b/crates/extensions/build.rs
index c7b657a..3788c03 100644
--- a/crates/extensions/build.rs
+++ b/crates/extensions/build.rs
@@ -5,7 +5,7 @@ fn compile(source_path: &str, output_path: &str) {
         .args([
             "-O3",
             "-filetype=asm",
-            "-mattr=+zbb,+e",
+            "-mattr=+zbb,+e,+m",
             source_path,
             "-o",
             output_path,
diff --git a/crates/llvm-context/Cargo.toml b/crates/llvm-context/Cargo.toml
index a740dc2..cbf0b58 100644
--- a/crates/llvm-context/Cargo.toml
+++ b/crates/llvm-context/Cargo.toml
@@ -33,3 +33,4 @@ pallet-contracts-pvm-llapi = { path = "../pallet-contracts-pvm-llapi" }
 revive-linker = { path = "../linker" }
 revive-builtins = { path = "../builtins" }
 revive-stdlib = { path = "../stdlib" }
+revive-extensions = { path = "../extensions" }
diff --git a/crates/llvm-context/src/eravm/context/mod.rs b/crates/llvm-context/src/eravm/context/mod.rs
index e76d3d6..75e72ec 100644
--- a/crates/llvm-context/src/eravm/context/mod.rs
+++ b/crates/llvm-context/src/eravm/context/mod.rs
@@ -122,6 +122,31 @@ where
     /// The PolkaVM minimum stack size.
     const POLKAVM_STACK_SIZE: u32 = 0x4000;
 
+    /// Link in the extensions module.
+    fn link_extensions_module(
+        llvm: &'ctx inkwell::context::Context,
+        module: &inkwell::module::Module<'ctx>,
+    ) {
+        module
+            .link_in_module(revive_extensions::module(llvm, "revive_extensions").unwrap())
+            .expect("the extensions module should be linkable");
+
+        let i256_type = llvm.custom_width_int_type(revive_common::BIT_LENGTH_FIELD as u32);
+        let bswap = module.add_function(
+            "__bswap",
+            i256_type.fn_type(&[i256_type.into()], false),
+            Some(inkwell::module::Linkage::External),
+        );
+        bswap.add_attribute(
+            inkwell::attributes::AttributeLoc::Function,
+            llvm.create_enum_attribute(Attribute::AlwaysInline as u32, 0),
+        );
+        bswap.add_attribute(
+            inkwell::attributes::AttributeLoc::Function,
+            llvm.create_enum_attribute(Attribute::WillReturn as u32, 0),
+        );
+    }
+
     /// Link in the stdlib module.
     fn link_stdlib_module(
         llvm: &'ctx inkwell::context::Context,
@@ -203,6 +228,7 @@ where
         debug_config: Option<DebugConfig>,
     ) -> Self {
         Self::link_stdlib_module(llvm, &module);
+        Self::link_extensions_module(llvm, &module);
         Self::link_polkavm_guest_module(llvm, &module);
         Self::set_polkavm_stack_size(llvm, &module, Self::POLKAVM_STACK_SIZE);
         Self::set_module_flags(llvm, &module);
@@ -703,7 +729,7 @@ where
                     .set_alignment(revive_common::BYTE_LENGTH_BYTE as u32)
                     .expect("Alignment is valid");
 
-                Ok(self.build_byte_swap(value))
+                self.build_byte_swap(value)
             }
             AddressSpace::TransientStorage => todo!(),
             AddressSpace::Storage => {
@@ -761,13 +787,13 @@ where
                 // TODO check return value
 
                 self.build_load(storage_value_pointer, "storage_value_load")
-                    .map(|value| self.build_byte_swap(value))
+                    .and_then(|value| self.build_byte_swap(value))
             }
             AddressSpace::Code | AddressSpace::HeapAuxiliary => todo!(),
-            AddressSpace::Generic => Ok(self.build_byte_swap(self.build_load(
+            AddressSpace::Generic => self.build_byte_swap(self.build_load(
                 pointer.address_space_cast(self, AddressSpace::Stack, &format!("{}_cast", name))?,
                 name,
-            )?)),
+            )?),
             AddressSpace::Stack => {
                 let value = self
                     .builder()
@@ -811,7 +837,7 @@ where
 
                 let value = value.as_basic_value_enum();
                 let value = match value.get_type().into_int_type().get_bit_width() as usize {
-                    revive_common::BIT_LENGTH_FIELD => self.build_byte_swap(value),
+                    revive_common::BIT_LENGTH_FIELD => self.build_byte_swap(value)?,
                     revive_common::BIT_LENGTH_BYTE => value,
                     _ => unreachable!("Only word and byte sized values can be stored on EVM heap"),
                 };
@@ -834,7 +860,7 @@ where
                     self.build_alloca(storage_key_value.get_type(), "storage_key");
 
                 let storage_value_value = self
-                    .build_byte_swap(value.as_basic_value_enum())
+                    .build_byte_swap(value.as_basic_value_enum())?
                     .into_int_value();
                 let storage_value_pointer =
                     self.build_alloca(storage_value_value.get_type(), "storage_value");
@@ -871,7 +897,7 @@ where
             AddressSpace::Code | AddressSpace::HeapAuxiliary => {}
             AddressSpace::Generic => self.build_store(
                 pointer.address_space_cast(self, AddressSpace::Stack, "cast")?,
-                self.build_byte_swap(value.as_basic_value_enum()),
+                self.build_byte_swap(value.as_basic_value_enum())?,
             )?,
             AddressSpace::Stack => {
                 let instruction = self.builder.build_store(pointer.value, value).unwrap();
@@ -888,9 +914,23 @@ where
     pub fn build_byte_swap(
         &self,
         value: inkwell::values::BasicValueEnum<'ctx>,
-    ) -> inkwell::values::BasicValueEnum<'ctx> {
-        self.build_call(self.intrinsics().byte_swap, &[value], "call_byte_swap")
-            .expect("byte_swap should return a value")
+    ) -> anyhow::Result<inkwell::values::BasicValueEnum<'ctx>> {
+        //return Ok(self
+        //    .build_call(self.intrinsics().byte_swap, &[value], "call_byte_swap")
+        //    .expect("__bswap should return a value"));
+
+        let function = self
+            .module()
+            .get_function("__bswap")
+            .expect("should be declared");
+
+        Ok(self
+            .builder()
+            .build_direct_call(function, &[value.into()], "call_byte_swap")?
+            .try_as_basic_value()
+            .left()
+            .expect("__bswap should return a value")
+            .into())
     }
 
     ///
diff --git a/crates/llvm-context/src/eravm/evm/calldata.rs b/crates/llvm-context/src/eravm/evm/calldata.rs
index 8a75a92..7fc3f7f 100644
--- a/crates/llvm-context/src/eravm/evm/calldata.rs
+++ b/crates/llvm-context/src/eravm/evm/calldata.rs
@@ -30,7 +30,7 @@ where
     );
     context
         .build_load(offset, "calldata_value")
-        .map(|value| context.build_byte_swap(value))
+        .and_then(|value| context.build_byte_swap(value))
 }
 
 ///
diff --git a/crates/llvm-context/src/eravm/evm/crypto.rs b/crates/llvm-context/src/eravm/evm/crypto.rs
index c301ef3..ab7a657 100644
--- a/crates/llvm-context/src/eravm/evm/crypto.rs
+++ b/crates/llvm-context/src/eravm/evm/crypto.rs
@@ -47,5 +47,5 @@ where
         "call_seal_hash_keccak_256",
     )?;
 
-    Ok(context.build_byte_swap(context.build_load(output_pointer, "sha3_output")?))
+    context.build_byte_swap(context.build_load(output_pointer, "sha3_output")?)
 }