diff --git a/runtime/crab/build.rs b/runtime/crab/build.rs
index 4a1101a97..05785b550 100644
--- a/runtime/crab/build.rs
+++ b/runtime/crab/build.rs
@@ -19,6 +19,10 @@
 // crates.io
 use substrate_wasm_builder::WasmBuilder;
 
+#[cfg(feature = "std")]
 fn main() {
 	WasmBuilder::new().with_current_project().export_heap_base().import_memory().build()
 }
+
+#[cfg(not(feature = "std"))]
+fn main() {}
diff --git a/runtime/darwinia/build.rs b/runtime/darwinia/build.rs
index 4a1101a97..05785b550 100644
--- a/runtime/darwinia/build.rs
+++ b/runtime/darwinia/build.rs
@@ -19,6 +19,10 @@
 // crates.io
 use substrate_wasm_builder::WasmBuilder;
 
+#[cfg(feature = "std")]
 fn main() {
 	WasmBuilder::new().with_current_project().export_heap_base().import_memory().build()
 }
+
+#[cfg(not(feature = "std"))]
+fn main() {}
diff --git a/runtime/pangolin/build.rs b/runtime/pangolin/build.rs
index 4a1101a97..05785b550 100644
--- a/runtime/pangolin/build.rs
+++ b/runtime/pangolin/build.rs
@@ -19,6 +19,10 @@
 // crates.io
 use substrate_wasm_builder::WasmBuilder;
 
+#[cfg(feature = "std")]
 fn main() {
 	WasmBuilder::new().with_current_project().export_heap_base().import_memory().build()
 }
+
+#[cfg(not(feature = "std"))]
+fn main() {}
diff --git a/runtime/pangoro/build.rs b/runtime/pangoro/build.rs
index 4a1101a97..05785b550 100644
--- a/runtime/pangoro/build.rs
+++ b/runtime/pangoro/build.rs
@@ -19,6 +19,10 @@
 // crates.io
 use substrate_wasm_builder::WasmBuilder;
 
+#[cfg(feature = "std")]
 fn main() {
 	WasmBuilder::new().with_current_project().export_heap_base().import_memory().build()
 }
+
+#[cfg(not(feature = "std"))]
+fn main() {}