diff --git a/integration-tests/call-runtime/Cargo.toml b/integration-tests/call-runtime/Cargo.toml
index 72aa67835a9..a6e2ac16a3a 100644
--- a/integration-tests/call-runtime/Cargo.toml
+++ b/integration-tests/call-runtime/Cargo.toml
@@ -41,3 +41,7 @@ e2e-tests = []
 # Assumes that the node used in E2E testing allows using the `call-runtime` API, including triggering
 # `Balances::transfer` extrinsic.
 permissive-node = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/contract-terminate/Cargo.toml b/integration-tests/contract-terminate/Cargo.toml
index d2834eb3c92..41b32d1a122 100644
--- a/integration-tests/contract-terminate/Cargo.toml
+++ b/integration-tests/contract-terminate/Cargo.toml
@@ -28,3 +28,7 @@ std = [
 ]
 ink-as-dependency = []
 e2e-tests = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/contract-transfer/Cargo.toml b/integration-tests/contract-transfer/Cargo.toml
index 1b54492d75b..0b0dd1e539d 100644
--- a/integration-tests/contract-transfer/Cargo.toml
+++ b/integration-tests/contract-transfer/Cargo.toml
@@ -28,3 +28,7 @@ std = [
 ]
 ink-as-dependency = []
 e2e-tests = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/custom-environment/Cargo.toml b/integration-tests/custom-environment/Cargo.toml
index 514d7ada7b4..b393fc2b3a6 100644
--- a/integration-tests/custom-environment/Cargo.toml
+++ b/integration-tests/custom-environment/Cargo.toml
@@ -29,3 +29,7 @@ e2e-tests = []
 
 # Assumes that the node used in E2E testing allows for at least 6 event topics.
 permissive-node = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/custom_allocator/Cargo.toml b/integration-tests/custom_allocator/Cargo.toml
index b77054071e5..6653c6f1e97 100755
--- a/integration-tests/custom_allocator/Cargo.toml
+++ b/integration-tests/custom_allocator/Cargo.toml
@@ -31,3 +31,7 @@ std = [
 ]
 ink-as-dependency = []
 e2e-tests = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/delegator/Cargo.toml b/integration-tests/delegator/Cargo.toml
index e1856d39a3f..409b6738812 100644
--- a/integration-tests/delegator/Cargo.toml
+++ b/integration-tests/delegator/Cargo.toml
@@ -43,3 +43,7 @@ members = [
     "adder",
     "subber",
 ]
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/delegator/accumulator/Cargo.toml b/integration-tests/delegator/accumulator/Cargo.toml
index f460417f813..b443751bd70 100644
--- a/integration-tests/delegator/accumulator/Cargo.toml
+++ b/integration-tests/delegator/accumulator/Cargo.toml
@@ -27,3 +27,7 @@ std = [
     "scale-info/std",
 ]
 ink-as-dependency = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/delegator/adder/Cargo.toml b/integration-tests/delegator/adder/Cargo.toml
index 2512c752b20..f32aef7662f 100644
--- a/integration-tests/delegator/adder/Cargo.toml
+++ b/integration-tests/delegator/adder/Cargo.toml
@@ -32,3 +32,7 @@ std = [
     "accumulator/std",
 ]
 ink-as-dependency = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/delegator/subber/Cargo.toml b/integration-tests/delegator/subber/Cargo.toml
index 475e0691122..8fb4d28d453 100644
--- a/integration-tests/delegator/subber/Cargo.toml
+++ b/integration-tests/delegator/subber/Cargo.toml
@@ -32,3 +32,7 @@ std = [
     "accumulator/std",
 ]
 ink-as-dependency = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/dns/Cargo.toml b/integration-tests/dns/Cargo.toml
index 9eb3733ec81..19c7923495c 100644
--- a/integration-tests/dns/Cargo.toml
+++ b/integration-tests/dns/Cargo.toml
@@ -24,3 +24,7 @@ std = [
     "scale-info/std",
 ]
 ink-as-dependency = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/erc1155/Cargo.toml b/integration-tests/erc1155/Cargo.toml
index 2e52ef6642c..f78900dffde 100644
--- a/integration-tests/erc1155/Cargo.toml
+++ b/integration-tests/erc1155/Cargo.toml
@@ -24,3 +24,7 @@ std = [
     "scale-info/std",
 ]
 ink-as-dependency = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/erc20/Cargo.toml b/integration-tests/erc20/Cargo.toml
index 2389805c87b..05626a4411f 100644
--- a/integration-tests/erc20/Cargo.toml
+++ b/integration-tests/erc20/Cargo.toml
@@ -28,3 +28,7 @@ std = [
 ]
 ink-as-dependency = []
 e2e-tests = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/erc721/Cargo.toml b/integration-tests/erc721/Cargo.toml
index f8d1cca5f3f..595ef8a3217 100644
--- a/integration-tests/erc721/Cargo.toml
+++ b/integration-tests/erc721/Cargo.toml
@@ -24,3 +24,7 @@ std = [
     "scale-info/std",
 ]
 ink-as-dependency = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/flipper/Cargo.toml b/integration-tests/flipper/Cargo.toml
index 324f87ddaec..3f25b6b1eeb 100644
--- a/integration-tests/flipper/Cargo.toml
+++ b/integration-tests/flipper/Cargo.toml
@@ -28,3 +28,7 @@ std = [
 ]
 ink-as-dependency = []
 e2e-tests = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/incrementer/Cargo.toml b/integration-tests/incrementer/Cargo.toml
index 173eb53c804..68d6219a711 100644
--- a/integration-tests/incrementer/Cargo.toml
+++ b/integration-tests/incrementer/Cargo.toml
@@ -24,3 +24,7 @@ std = [
     "scale-info/std",
 ]
 ink-as-dependency = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/lang-err-integration-tests/call-builder/Cargo.toml b/integration-tests/lang-err-integration-tests/call-builder/Cargo.toml
index 008615d68df..11f5218bf80 100755
--- a/integration-tests/lang-err-integration-tests/call-builder/Cargo.toml
+++ b/integration-tests/lang-err-integration-tests/call-builder/Cargo.toml
@@ -37,3 +37,7 @@ std = [
 ]
 ink-as-dependency = []
 e2e-tests = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/lang-err-integration-tests/constructors-return-value/Cargo.toml b/integration-tests/lang-err-integration-tests/constructors-return-value/Cargo.toml
index 6d4dfa6bce0..674984eaea0 100644
--- a/integration-tests/lang-err-integration-tests/constructors-return-value/Cargo.toml
+++ b/integration-tests/lang-err-integration-tests/constructors-return-value/Cargo.toml
@@ -33,3 +33,7 @@ std = [
 ]
 ink-as-dependency = []
 e2e-tests = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/lang-err-integration-tests/contract-ref/Cargo.toml b/integration-tests/lang-err-integration-tests/contract-ref/Cargo.toml
index 8801797b2f2..6767acae059 100755
--- a/integration-tests/lang-err-integration-tests/contract-ref/Cargo.toml
+++ b/integration-tests/lang-err-integration-tests/contract-ref/Cargo.toml
@@ -34,3 +34,7 @@ std = [
 ]
 ink-as-dependency = []
 e2e-tests = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/lang-err-integration-tests/integration-flipper/Cargo.toml b/integration-tests/lang-err-integration-tests/integration-flipper/Cargo.toml
index fa037e62d55..25ddc7e7245 100644
--- a/integration-tests/lang-err-integration-tests/integration-flipper/Cargo.toml
+++ b/integration-tests/lang-err-integration-tests/integration-flipper/Cargo.toml
@@ -33,3 +33,7 @@ std = [
 ]
 ink-as-dependency = []
 e2e-tests = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/mapping_integration_tests/Cargo.toml b/integration-tests/mapping_integration_tests/Cargo.toml
index ce9d51ce890..e780ed3fca8 100755
--- a/integration-tests/mapping_integration_tests/Cargo.toml
+++ b/integration-tests/mapping_integration_tests/Cargo.toml
@@ -31,3 +31,7 @@ std = [
 ]
 ink-as-dependency = []
 e2e-tests = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/mother/Cargo.toml b/integration-tests/mother/Cargo.toml
index 4e322fcc514..b49f17d86ff 100755
--- a/integration-tests/mother/Cargo.toml
+++ b/integration-tests/mother/Cargo.toml
@@ -31,3 +31,7 @@ std = [
     "scale-info/std",
 ]
 ink-as-dependency = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/multisig/Cargo.toml b/integration-tests/multisig/Cargo.toml
index 76eeb76a866..44cb3393a95 100755
--- a/integration-tests/multisig/Cargo.toml
+++ b/integration-tests/multisig/Cargo.toml
@@ -24,3 +24,7 @@ std = [
     "scale-info/std",
 ]
 ink-as-dependency = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/payment-channel/Cargo.toml b/integration-tests/payment-channel/Cargo.toml
index ccfc677d215..25ff1043fd1 100755
--- a/integration-tests/payment-channel/Cargo.toml
+++ b/integration-tests/payment-channel/Cargo.toml
@@ -29,3 +29,7 @@ std = [
 ]
 
 ink-as-dependency = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/psp22-extension/Cargo.toml b/integration-tests/psp22-extension/Cargo.toml
index ec09dbad0f2..4bdbdfdc307 100755
--- a/integration-tests/psp22-extension/Cargo.toml
+++ b/integration-tests/psp22-extension/Cargo.toml
@@ -24,3 +24,7 @@ std = [
     "scale-info/std",
 ]
 ink-as-dependency = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/rand-extension/Cargo.toml b/integration-tests/rand-extension/Cargo.toml
index 1007ad2b03d..6958661188e 100755
--- a/integration-tests/rand-extension/Cargo.toml
+++ b/integration-tests/rand-extension/Cargo.toml
@@ -24,3 +24,7 @@ std = [
     "scale-info/std",
 ]
 ink-as-dependency = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/trait-erc20/Cargo.toml b/integration-tests/trait-erc20/Cargo.toml
index b19515e7a49..00acaa0eac4 100644
--- a/integration-tests/trait-erc20/Cargo.toml
+++ b/integration-tests/trait-erc20/Cargo.toml
@@ -24,3 +24,7 @@ std = [
     "scale-info/std",
 ]
 ink-as-dependency = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/trait-flipper/Cargo.toml b/integration-tests/trait-flipper/Cargo.toml
index 49d6a4265c0..bab23837980 100644
--- a/integration-tests/trait-flipper/Cargo.toml
+++ b/integration-tests/trait-flipper/Cargo.toml
@@ -24,3 +24,7 @@ std = [
     "scale-info/std",
 ]
 ink-as-dependency = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/trait-incrementer/Cargo.toml b/integration-tests/trait-incrementer/Cargo.toml
index 5f308627e56..08f2942da36 100644
--- a/integration-tests/trait-incrementer/Cargo.toml
+++ b/integration-tests/trait-incrementer/Cargo.toml
@@ -26,3 +26,7 @@ std = [
     "traits/std",
 ]
 ink-as-dependency = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/trait-incrementer/traits/Cargo.toml b/integration-tests/trait-incrementer/traits/Cargo.toml
index cd0f8d74311..a70c628436d 100644
--- a/integration-tests/trait-incrementer/traits/Cargo.toml
+++ b/integration-tests/trait-incrementer/traits/Cargo.toml
@@ -24,3 +24,7 @@ std = [
     "scale-info/std",
 ]
 ink-as-dependency = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/upgradeable-contracts/forward-calls/Cargo.toml b/integration-tests/upgradeable-contracts/forward-calls/Cargo.toml
index 4173183631d..fdae3300c42 100644
--- a/integration-tests/upgradeable-contracts/forward-calls/Cargo.toml
+++ b/integration-tests/upgradeable-contracts/forward-calls/Cargo.toml
@@ -24,3 +24,7 @@ std = [
     "scale-info/std",
 ]
 ink-as-dependency = []
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/upgradeable-contracts/set-code-hash/Cargo.toml b/integration-tests/upgradeable-contracts/set-code-hash/Cargo.toml
index 27b102b19b7..31b99af94d4 100644
--- a/integration-tests/upgradeable-contracts/set-code-hash/Cargo.toml
+++ b/integration-tests/upgradeable-contracts/set-code-hash/Cargo.toml
@@ -28,3 +28,7 @@ std = [
 ink-as-dependency = []
 
 
+
+[profile.release]
+opt-level = 's'
+lto = true
diff --git a/integration-tests/upgradeable-contracts/set-code-hash/updated-incrementer/Cargo.toml b/integration-tests/upgradeable-contracts/set-code-hash/updated-incrementer/Cargo.toml
index 0667cb79c30..eeeccfdd58d 100644
--- a/integration-tests/upgradeable-contracts/set-code-hash/updated-incrementer/Cargo.toml
+++ b/integration-tests/upgradeable-contracts/set-code-hash/updated-incrementer/Cargo.toml
@@ -26,3 +26,7 @@ std = [
     "scale-info/std",
 ]
 ink-as-dependency = []
+
+[profile.release]
+opt-level = 's'
+lto = true