diff --git a/library/core/Cargo.toml b/library/core/Cargo.toml
index b7c6db6c78dde..4d69f0d83deca 100644
--- a/library/core/Cargo.toml
+++ b/library/core/Cargo.toml
@@ -31,6 +31,7 @@ check-cfg = [
     'cfg(no_fp_fmt_parse)',
     'cfg(stdarch_intel_sde)',
     'cfg(target_arch, values("xtensa"))',
+    'cfg(test)',
     # core use #[path] imports to portable-simd `core_simd` crate
     # and to stdarch `core_arch` crate which messes-up with Cargo list
     # of declared features, we therefor expect any feature cfg