diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index aa2b90ab3bdf5251bc14c8bcd3cbb3c2ab0a92a0..0dca805c9aed364a30011fa7abc9ab525abd9942 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -85,7 +85,8 @@ test:
   stage:                           test
   <<:                              *docker-env
   script:
-    - cargo test --verbose --workspace --all-features
+    - rustup override set nightly-2022-01-19
+    - cargo +nightly test --verbose --workspace --all-features
 
 test-new-project-template:
   stage:                           test
diff --git a/src/cmd/test.rs b/src/cmd/test.rs
index 3e31862b4d4b0827eab95a20ebeb397e5905c592..98b9dae139323e2ddd158987e0e30666a75f2072 100644
--- a/src/cmd/test.rs
+++ b/src/cmd/test.rs
@@ -65,9 +65,6 @@ pub(crate) fn execute(manifest_path: &ManifestPath, verbosity: Verbosity) -> Res
         "Running tests".bright_green().bold()
     );
 
-    // We need to make sure that `RUSTFLAGS` are not set in the CI here.
-    // `cargo-contract` sets them when building contracts.
-    std::env::set_var("RUSTFLAGS", "");
     let stdout = util::invoke_cargo("test", &[""], manifest_path.directory(), verbosity)?;
 
     Ok(TestResult { stdout, verbosity })