diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7c5c195d..cbe3cfd0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,8 @@ Note: In this file, do not use the hard wrap in the middle of a sentence for com
 
 ## [Unreleased]
 
+- Limit the number of test threads to work around [rust-lang/rust#91092](https://github.com/rust-lang/rust/issues/91092). ([#184](https://github.com/taiki-e/cargo-llvm-cov/pull/184))
+
 ## [0.4.5] - 2022-06-02
 
 - Fix handling of `RUSTC_WRAPPER`, `RUSTC`, and similar environment variables and configs. ([#180](https://github.com/taiki-e/cargo-llvm-cov/pull/180))
diff --git a/src/main.rs b/src/main.rs
index b13da4dd..371984eb 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -294,6 +294,8 @@ fn set_env(cx: &Context, target: &mut impl EnvTarget) {
     }
     target.set("LLVM_PROFILE_FILE", llvm_profile_file.as_str());
     target.set("CARGO_INCREMENTAL", "0");
+    // Workaround for https://github.com/rust-lang/rust/issues/91092
+    target.set("RUST_TEST_THREADS", "1");
 }
 
 fn has_z_flag(args: &Args, name: &str) -> bool {