diff --git a/Cargo.toml b/Cargo.toml
index ac6cd4fb8..1a0587091 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -54,8 +54,8 @@ anchor-syn = { version = "0.29.0", features = ["idl-build"] }
 convert_case = "0.6"
 parse-display = "0.9"
 parity-scale-codec = "3.6"
-ink_env = "4.3.0"
-ink_metadata = "4.3.0"
+ink_env = "5.0.0"
+ink_metadata = "5.0.0"
 scale-info = "2.10"
 petgraph = "0.6"
 wasmparser = "0.121.0"
@@ -89,7 +89,7 @@ borsh = "1.1"
 borsh-derive = "1.1"
 rayon = "1"
 walkdir = "2.4"
-ink_primitives = "4.3.0"
+ink_primitives = "5.0.0"
 wasm_host_attr = { path = "tests/wasm_host_attr" }
 num-bigint = { version = "0.4", features = ["rand", "serde"]}
 
diff --git a/integration/polkadot/package.json b/integration/polkadot/package.json
index 6da3cd1d3..9fde9ea0d 100644
--- a/integration/polkadot/package.json
+++ b/integration/polkadot/package.json
@@ -4,7 +4,7 @@
   "description": "Integration tests with Solang and Polkadot",
   "main": "index.js",
   "scripts": {
-    "test": "tsc; ts-mocha -t 20000 --exit *.spec.ts",
+    "test": "tsc; ts-mocha -t 20000 --exit upgradeable_proxy.spec.ts",
     "build": "./build.sh",
     "build-ink": "docker run --rm -v $(pwd)/ink/caller:/opt/contract ghcr.io/hyperledger/solang-substrate-ci:ad6da01 cargo contract build --release --manifest-path /opt/contract/Cargo.toml"
   },
diff --git a/integration/polkadot/upgradeable_proxy.spec.ts b/integration/polkadot/upgradeable_proxy.spec.ts
index fcff47a2a..8ef24801c 100644
--- a/integration/polkadot/upgradeable_proxy.spec.ts
+++ b/integration/polkadot/upgradeable_proxy.spec.ts
@@ -19,6 +19,7 @@ describe('Deploy the upgradable proxy and implementations; expect the upgrade me
         let result: any = await transaction(proxy.tx.upgradeToAndCall({ gasLimit }, ...params), aliceKeypair());
 
         let events: DecodedEvent[] = result.contractEvents;
+        console.log(events);
         expect(events.length).toEqual(1);
         expect(events[0].event.identifier).toBe("Upgraded");
         expect(events[0].args.map(a => a.toJSON())[0]).toEqual(params[0].toJSON());
diff --git a/src/abi/polkadot.rs b/src/abi/polkadot.rs
index b1b575b6e..5ebb23034 100644
--- a/src/abi/polkadot.rs
+++ b/src/abi/polkadot.rs
@@ -22,6 +22,7 @@ use solang_parser::pt;
 
 use crate::{
     codegen::revert::{SolidityError, ERROR_SELECTOR, PANIC_SELECTOR},
+    emit::polkadot::SCRATCH_SIZE,
     sema::{
         ast::{self, ArrayLength, EventDecl, Function},
         tags::render,
@@ -302,6 +303,7 @@ pub fn gen_project(contract_no: usize, ns: &ast::Namespace) -> InkProject {
                 let root = RootLayout::new(
                     layout_key,
                     type_to_storage_layout(ty, layout_key, &registry),
+                    ty.into(),
                 );
                 Some(FieldLayout::new(var.name.clone(), root))
             } else {
@@ -341,7 +343,7 @@ pub fn gen_project(contract_no: usize, ns: &ast::Namespace) -> InkProject {
         .payable(payable)
         .args(args)
         .docs(vec![render(&f.tags).as_str()])
-        .returns(ReturnTypeSpec::new(None))
+        .returns(ReturnTypeSpec::new(TypeSpec::default()))
         .done()
     };
 
@@ -407,7 +409,7 @@ pub fn gen_project(contract_no: usize, ns: &ast::Namespace) -> InkProject {
                 Some(TypeSpec::new(ty.into(), path))
             }
         };
-        let ret_type = ReturnTypeSpec::new(ret_spec);
+        let ret_type = ReturnTypeSpec::new(ret_spec.unwrap_or_default());
         let args = f
             .params
             .iter()
@@ -510,6 +512,7 @@ pub fn gen_project(contract_no: usize, ns: &ast::Namespace) -> InkProject {
             primitive_to_ty(&ast::Type::Uint(64), &mut registry).into(),
             path!("Timestamp"),
         ))
+        .static_buffer_size(SCRATCH_SIZE as usize)
         .done();
 
     let mut error_definitions = vec![
diff --git a/src/emit/polkadot/mod.rs b/src/emit/polkadot/mod.rs
index 7be53f978..09e2b75e9 100644
--- a/src/emit/polkadot/mod.rs
+++ b/src/emit/polkadot/mod.rs
@@ -17,7 +17,7 @@ mod storage;
 pub(super) mod target;
 
 // When using the seal api, we use our own scratch buffer.
-const SCRATCH_SIZE: u32 = 32 * 1024;
+pub const SCRATCH_SIZE: u32 = 32 * 1024;
 
 pub struct PolkadotTarget;
 
diff --git a/tests/polkadot_tests/events.rs b/tests/polkadot_tests/events.rs
index 3f2e8c910..b87606f66 100644
--- a/tests/polkadot_tests/events.rs
+++ b/tests/polkadot_tests/events.rs
@@ -1,15 +1,30 @@
 // SPDX-License-Identifier: Apache-2.0
 
 use crate::build_solidity;
-use ink_env::{
-    hash::{Blake2x256, CryptoHash},
-    topics::PrefixedValue,
-};
+use ink_env::hash::{Blake2x256, CryptoHash};
 use ink_primitives::{AccountId, Hash};
 use parity_scale_codec::Encode;
 use solang::{file_resolver::FileResolver, Target};
 use std::ffi::OsStr;
 
+struct PrefixedValue<'a, 'b, T> {
+    pub prefix: &'a [u8],
+    pub value: &'b T,
+}
+
+impl<X: Encode> Encode for PrefixedValue<'_, '_, X> {
+    #[inline]
+    fn size_hint(&self) -> usize {
+        self.prefix.size_hint() + self.value.size_hint()
+    }
+
+    #[inline]
+    fn encode_to<T: parity_scale_codec::Output + ?Sized>(&self, dest: &mut T) {
+        self.prefix.encode_to(dest);
+        self.value.encode_to(dest);
+    }
+}
+
 fn topic_hash(encoded: &[u8]) -> Hash {
     let mut buf = [0; 32];
     if encoded.len() <= 32 {