diff --git a/substrate/primitives/api/test/tests/trybuild.rs b/substrate/primitives/api/test/tests/trybuild.rs
index bf51365f002e..b13e5df9d6f8 100644
--- a/substrate/primitives/api/test/tests/trybuild.rs
+++ b/substrate/primitives/api/test/tests/trybuild.rs
@@ -25,7 +25,7 @@ fn ui() {
 	}
 
 	// As trybuild is using `cargo check`, we don't need the real WASM binaries.
-	env::set_var("SKIP_WASM_BUILD", "1");
+	std::env::set_var("SKIP_WASM_BUILD", "1");
 
 	// Warnings are part of our UI.
 	std::env::set_var("RUSTFLAGS", "--deny warnings");
diff --git a/substrate/primitives/runtime-interface/tests/ui.rs b/substrate/primitives/runtime-interface/tests/ui.rs
index e6a2a3821fc9..408ddbc981ee 100644
--- a/substrate/primitives/runtime-interface/tests/ui.rs
+++ b/substrate/primitives/runtime-interface/tests/ui.rs
@@ -24,7 +24,7 @@ fn ui() {
 	}
 
 	// As trybuild is using `cargo check`, we don't need the real WASM binaries.
-	env::set_var("SKIP_WASM_BUILD", "1");
+	std::env::set_var("SKIP_WASM_BUILD", "1");
 
 	let t = trybuild::TestCases::new();
 	t.compile_fail("tests/ui/*.rs");