diff --git a/src/main.rs b/src/main.rs
index 2e66aee..473148f 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -33,6 +33,7 @@ use crate::core::resolve_envrc_context;
     QUICKENV_NO_SHIM=1 to disable loading of .envrc, and effectively disable shims
     QUICKENV_SHIM_EXEC=1 to directly exec() shims instead of spawning them as subprocess. This can help with attaching debuggers.
     QUICKENV_NO_SHIM_WARNINGS=1 to disable nags about running 'quickenv shim' everytime a new binary is added
+    QUICKENV_PRELUDE='eval \"$(direnv stdlib)\"' can be overridden to something else to get rid of the direnv stdlib and therefore direnv dependency, or to inject additional code before executing each envrc.
 "
 )]
 struct Args {
@@ -275,49 +276,45 @@ fn compute_envvars(quickenv_home: &Path) -> Result<(), Error> {
     })?;
     let mut temp_script = tempfile::NamedTempFile::new_in(&ctx.root)
         .with_context(|| format!("failed to create temporary file at {}", ctx.root.display()))?;
+    let temp_script_path = temp_script.path().to_owned();
 
-    temp_script
-        .write_all(
-            br#"
+    let write_failure = || {
+        format!(
+            "failed to write to temporary file at {}",
+            temp_script_path.display()
+        )
+    };
+
+    let prelude = std::env::var("QUICKENV_PRELUDE")
+        .unwrap_or_else(|_| r#"eval "$(direnv stdlib)""#.to_owned());
+
+    write!(
+        temp_script,
+        r##"
 echo '// BEGIN QUICKENV-BEFORE'
 env
 echo '// END QUICKENV-BEFORE'
-eval "$(direnv stdlib)"
-"#,
-        )
-        .with_context(|| {
-            format!(
-                "failed to write to temporary file at {}",
-                temp_script.path().display()
-            )
-        })?;
+{prelude}
+"##,
+    )
+    .with_context(write_failure)?;
 
-    io::copy(&mut ctx.envrc, &mut temp_script).with_context(|| {
-        format!(
-            "failed to write to temporary file at {}",
-            temp_script.path().display()
-        )
-    })?;
+    io::copy(&mut ctx.envrc, &mut temp_script).with_context(write_failure)?;
 
-    temp_script
-        .write_all(
-            br#"
+    write!(
+        temp_script,
+        r##"
 echo '// BEGIN QUICKENV-AFTER'
 env
 echo '// END QUICKENV-AFTER'
-"#,
-        )
-        .with_context(|| {
-            format!(
-                "failed to write to temporary file at {}",
-                temp_script.path().display()
-            )
-        })?;
+"##
+    )
+    .with_context(write_failure)?;
 
     signals::pass_control_to_shim();
 
     let mut cmd = process::Command::new("bash")
-        .arg(temp_script.path())
+        .arg(&temp_script_path)
         .env("QUICKENV_NO_SHIM", "1")
         .stdin(Stdio::inherit())
         .stdout(Stdio::piped())
diff --git a/tests/acceptance_helpers.rs b/tests/acceptance_helpers.rs
index 1aef7a1..f5b8476 100644
--- a/tests/acceptance_helpers.rs
+++ b/tests/acceptance_helpers.rs
@@ -11,7 +11,7 @@ use tempfile::TempDir;
 
 pub struct Harness {
     pub env: BTreeMap<OsString, OsString>,
-    pub home: TempDir,
+    pub home: Option<TempDir>,
     pub cwd: PathBuf,
 }
 
@@ -73,6 +73,14 @@ impl Harness {
     }
 }
 
+impl Drop for Harness {
+    fn drop(&mut self) {
+        if std::env::var("QUICKENV_TEST_LEAK_FILES").unwrap_or_default() == "1" {
+            std::mem::forget(self.home.take());
+        }
+    }
+}
+
 pub fn setup() -> Result<Harness, Error> {
     let home = tempfile::tempdir()?;
     // on macos, /tmp is a symlink to /private/..., so sometimes the path reported by tmpdir is not
@@ -82,7 +90,7 @@ pub fn setup() -> Result<Harness, Error> {
     create_dir_all(&cwd)?;
     let mut harness = Harness {
         env: BTreeMap::new(),
-        home,
+        home: Some(home),
         cwd,
     };
 
@@ -114,6 +122,7 @@ macro_rules! assert_cmd {
         insta_cmd::assert_cmd_snapshot!(
             Command::new($harness.which(stringify!($program_name))?)
             .current_dir(&$harness.cwd)
+            .env_remove("QUICKENV_PRELUDE")
             .envs(&$harness.env)
             $(.arg($arg))*,
             $($insta_args)*