diff --git a/README.md b/README.md
index 426b6f74..cf343ee3 100644
--- a/README.md
+++ b/README.md
@@ -597,7 +597,7 @@ Note: AUR package is maintained by community, not maintainer of cargo-llvm-cov.
 
 - Branch coverage is not supported yet. See [#8] and [rust-lang/rust#79649] for more.
 - Support for doc tests is unstable and has known issues. See [#2] and [rust-lang/rust#79417] for more.
-- All the tests are run with `RUST_TEST_THREADS=1` to work around [rust-lang/rust#91092]. You can pass `--test-threads` (e.g., `--test-threads=$(nproc)`) to override this behavior.
+- All the tests are run with `RUST_TEST_THREADS=1` to work around [rust-lang/rust#91092]. You can pass `--test-threads` (e.g., `--test-threads=$(nproc)`) to override this behavior. (As for `nextest`, we also set `NEXTEST_TEST_THREADS=1`.)
 
 See also [the code-coverage-related issues reported in rust-lang/rust](https://github.com/rust-lang/rust/labels/A-code-coverage).
 
diff --git a/src/main.rs b/src/main.rs
index 7af63239..5cf0a875 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -82,7 +82,7 @@ fn try_main() -> Result<()> {
             let stdout = io::stdout();
             let writer =
                 &mut ShowEnvWriter { target: stdout.lock(), options: cx.args.show_env.clone() };
-            set_env(cx, writer)?;
+            set_env(cx, writer, IsNextest(true))?; // Include envs for nextest.
             writer.set("CARGO_LLVM_COV_TARGET_DIR", cx.ws.metadata.target_directory.as_str())?;
         }
         Subcommand::Report => {
@@ -163,7 +163,9 @@ impl<W: io::Write> EnvTarget for ShowEnvWriter<W> {
     }
 }
 
-fn set_env(cx: &Context, env: &mut dyn EnvTarget) -> Result<()> {
+struct IsNextest(bool);
+
+fn set_env(cx: &Context, env: &mut dyn EnvTarget, IsNextest(is_nextest): IsNextest) -> Result<()> {
     fn push_common_flags(cx: &Context, flags: &mut String) {
         if cx.ws.stable_coverage {
             flags.push_str(" -C instrument-coverage");
@@ -252,6 +254,10 @@ fn set_env(cx: &Context, env: &mut dyn EnvTarget) -> Result<()> {
     env.set("CARGO_INCREMENTAL", "0")?;
     // Workaround for https://github.com/rust-lang/rust/issues/91092
     env.set("RUST_TEST_THREADS", "1")?;
+    if is_nextest {
+        // Same as above
+        env.set("NEXTEST_TEST_THREADS", "1")?;
+    }
     Ok(())
 }
 
@@ -277,7 +283,7 @@ fn has_z_flag(args: &[String], name: &str) -> bool {
 fn run_test(cx: &Context) -> Result<()> {
     let mut cargo = cx.cargo();
 
-    set_env(cx, &mut cargo)?;
+    set_env(cx, &mut cargo, IsNextest(false))?;
 
     cargo.arg("test");
     if cx.args.doctests && !has_z_flag(&cx.args.cargo_args, "doctest-in-workspace") {
@@ -324,7 +330,7 @@ fn run_test(cx: &Context) -> Result<()> {
 fn run_nextest(cx: &Context) -> Result<()> {
     let mut cargo = cx.cargo();
 
-    set_env(cx, &mut cargo)?;
+    set_env(cx, &mut cargo, IsNextest(true))?;
 
     cargo.arg("nextest").arg("run");
 
@@ -345,7 +351,7 @@ fn run_nextest(cx: &Context) -> Result<()> {
 fn run_run(cx: &Context) -> Result<()> {
     let mut cargo = cx.cargo();
 
-    set_env(cx, &mut cargo)?;
+    set_env(cx, &mut cargo, IsNextest(false))?;
 
     if cx.args.ignore_run_fail {
         {