diff --git a/aleph-client/Cargo.lock b/aleph-client/Cargo.lock
index 9d18828332..34b679cfc2 100644
--- a/aleph-client/Cargo.lock
+++ b/aleph-client/Cargo.lock
@@ -49,7 +49,7 @@ dependencies = [
 
 [[package]]
 name = "aleph_client"
-version = "2.11.0"
+version = "2.12.0"
 dependencies = [
  "anyhow",
  "async-trait",
diff --git a/aleph-client/Cargo.toml b/aleph-client/Cargo.toml
index aa89266191..95f31e96e0 100644
--- a/aleph-client/Cargo.toml
+++ b/aleph-client/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "aleph_client"
-version = "2.11.0"
+version = "2.12.0"
 edition = "2021"
 license = "Apache 2.0"
 
diff --git a/aleph-client/src/contract/mod.rs b/aleph-client/src/contract/mod.rs
index 077fa4eaf9..242f49f7db 100644
--- a/aleph-client/src/contract/mod.rs
+++ b/aleph-client/src/contract/mod.rs
@@ -59,23 +59,43 @@ use crate::{
     AccountId, Balance, ConnectionApi, SignedConnectionApi, TxStatus,
 };
 
+/// Default gas limit, which allows up to 25% of block time (62.5% of the actual block capacity).
+pub const DEFAULT_MAX_GAS: u64 = 250_000_000_000u64;
+/// Default proof size limit, which allows up to 25% of block time (62.5% of the actual block
+/// capacity).
+pub const DEFAULT_MAX_PROOF_SIZE: u64 = 250_000_000_000u64;
+
 /// Represents a contract instantiated on the chain.
 pub struct ContractInstance {
     address: AccountId,
     transcoder: ContractMessageTranscoder,
+    max_gas_override: Option<u64>,
+    max_proof_size_override: Option<u64>,
 }
 
 impl ContractInstance {
-    const MAX_GAS: u64 = 10000000000u64;
-
     /// Creates a new contract instance under `address` with metadata read from `metadata_path`.
     pub fn new(address: AccountId, metadata_path: &str) -> Result<Self> {
         Ok(Self {
             address,
             transcoder: ContractMessageTranscoder::load(metadata_path)?,
+            max_gas_override: None,
+            max_proof_size_override: None,
         })
     }
 
+    /// From now on, the contract instance will use `limit_override` as the gas limit for all
+    /// contract calls. If `limit_override` is `None`, then [DEFAULT_MAX_GAS] will be used.
+    pub fn override_gas_limit(&mut self, limit_override: Option<u64>) {
+        self.max_gas_override = limit_override;
+    }
+
+    /// From now on, the contract instance will use `limit_override` as the proof size limit for all
+    /// contract calls. If `limit_override` is `None`, then [DEFAULT_MAX_PROOF_SIZE] will be used.
+    pub fn override_proof_size_limit(&mut self, limit_override: Option<u64>) {
+        self.max_proof_size_override = limit_override;
+    }
+
     /// The address of this contract instance.
     pub fn address(&self) -> &AccountId {
         &self.address
@@ -168,8 +188,10 @@ impl ContractInstance {
             self.address.clone(),
             value,
             Weight {
-                ref_time: Self::MAX_GAS,
-                proof_size: Self::MAX_GAS,
+                ref_time: self.max_gas_override.unwrap_or(DEFAULT_MAX_GAS),
+                proof_size: self
+                    .max_proof_size_override
+                    .unwrap_or(DEFAULT_MAX_PROOF_SIZE),
             },
             None,
             data,
diff --git a/benches/payout-stakers/Cargo.lock b/benches/payout-stakers/Cargo.lock
index c989b6e7f8..ff4de412e7 100644
--- a/benches/payout-stakers/Cargo.lock
+++ b/benches/payout-stakers/Cargo.lock
@@ -49,7 +49,7 @@ dependencies = [
 
 [[package]]
 name = "aleph_client"
-version = "2.11.0"
+version = "2.12.0"
 dependencies = [
  "anyhow",
  "async-trait",
diff --git a/bin/cliain/Cargo.lock b/bin/cliain/Cargo.lock
index 2b31f33e68..36f550dc83 100644
--- a/bin/cliain/Cargo.lock
+++ b/bin/cliain/Cargo.lock
@@ -49,7 +49,7 @@ dependencies = [
 
 [[package]]
 name = "aleph_client"
-version = "2.11.0"
+version = "2.12.0"
 dependencies = [
  "anyhow",
  "async-trait",
diff --git a/e2e-tests/Cargo.lock b/e2e-tests/Cargo.lock
index 8c7d5f5cb3..65e4f412e7 100644
--- a/e2e-tests/Cargo.lock
+++ b/e2e-tests/Cargo.lock
@@ -78,7 +78,7 @@ dependencies = [
 
 [[package]]
 name = "aleph_client"
-version = "2.11.0"
+version = "2.12.0"
 dependencies = [
  "anyhow",
  "async-trait",
diff --git a/flooder/Cargo.lock b/flooder/Cargo.lock
index 305eb625fa..1a7a86ab31 100644
--- a/flooder/Cargo.lock
+++ b/flooder/Cargo.lock
@@ -49,7 +49,7 @@ dependencies = [
 
 [[package]]
 name = "aleph_client"
-version = "2.11.0"
+version = "2.12.0"
 dependencies = [
  "anyhow",
  "async-trait",