diff --git a/crates/configuration/src/network.rs b/crates/configuration/src/network.rs
index 5bef574bd5b95719ee1822860c568f1cca3d331c..1bb0223717aee8cd12547c171a3ddd288f91a07e 100644
--- a/crates/configuration/src/network.rs
+++ b/crates/configuration/src/network.rs
@@ -133,7 +133,7 @@ impl NetworkConfigBuilder<WithRelaychain> {
         match f(ParachainConfigBuilder::new()).build() {
             Ok(parachain) => Self::transition(
                 NetworkConfig {
-                    parachains: vec![self.config.parachains, vec![parachain]].concat(),
+                    parachains: [self.config.parachains, vec![parachain]].concat(),
                     ..self.config
                 },
                 self.errors,
@@ -152,7 +152,7 @@ impl NetworkConfigBuilder<WithRelaychain> {
 
         Self::transition(
             NetworkConfig {
-                hrmp_channels: vec![self.config.hrmp_channels, vec![new_hrmp_channel]].concat(),
+                hrmp_channels: [self.config.hrmp_channels, vec![new_hrmp_channel]].concat(),
                 ..self.config
             },
             self.errors,
diff --git a/crates/configuration/src/parachain.rs b/crates/configuration/src/parachain.rs
index a0254c9091bcdfc53acd0da9c5e7447fd661fb45..84dc81f2c36c9ddfa7ad9258540b2e011ae4445e 100644
--- a/crates/configuration/src/parachain.rs
+++ b/crates/configuration/src/parachain.rs
@@ -480,7 +480,7 @@ impl ParachainConfigBuilder<WithAtLeastOneCollator> {
         match f(NodeConfigBuilder::new(ChainDefaultContext::default())).build() {
             Ok(collator) => Self::transition(
                 ParachainConfig {
-                    collators: vec![self.config.collators, vec![collator]].concat(),
+                    collators: [self.config.collators, vec![collator]].concat(),
                     ..self.config
                 },
                 self.errors,
diff --git a/crates/configuration/src/relaychain.rs b/crates/configuration/src/relaychain.rs
index 8bffcff9fee7a049de78181015920dbf3da50d29..ad437f29653d38c34a0e4e9299624039aa839102 100644
--- a/crates/configuration/src/relaychain.rs
+++ b/crates/configuration/src/relaychain.rs
@@ -317,7 +317,7 @@ impl RelaychainConfigBuilder<WithAtLeastOneNode> {
         match f(NodeConfigBuilder::new(self.default_context())).build() {
             Ok(node) => Self::transition(
                 RelaychainConfig {
-                    nodes: vec![self.config.nodes, vec![node]].concat(),
+                    nodes: [self.config.nodes, vec![node]].concat(),
                     ..self.config
                 },
                 self.errors,