diff --git a/tests/common/integration.rs b/tests/common/integration.rs
index 5e300efb5..84e1f5dc4 100644
--- a/tests/common/integration.rs
+++ b/tests/common/integration.rs
@@ -38,25 +38,25 @@ pub fn test_integration(
     let shed = format!("test-crates/wheels/{unique_name}");
     let target_dir = format!("test-crates/targets/{unique_name}");
     let python_interp = test_python_path();
-    let mut cli = vec![
-        "build",
-        "--quiet",
-        "--manifest-path",
-        &package_string,
-        "--target-dir",
-        &target_dir,
-        "--out",
-        &shed,
+    let mut cli: Vec<std::ffi::OsString> = vec![
+        "build".into(),
+        "--quiet".into(),
+        "--manifest-path".into(),
+        package_string.into(),
+        "--target-dir".into(),
+        target_dir.into(),
+        "--out".into(),
+        shed.into(),
     ];
 
     if let Some(ref bindings) = bindings {
-        cli.push("--bindings");
-        cli.push(bindings);
+        cli.push("--bindings".into());
+        cli.push(bindings.into());
     }
 
     if let Some(target) = target {
-        cli.push("--target");
-        cli.push(target)
+        cli.push("--target".into());
+        cli.push(target.into())
     }
 
     #[cfg(feature = "zig")]
@@ -65,11 +65,11 @@ pub fn test_integration(
     let zig_found = false;
 
     let test_zig = if zig && (env::var("GITHUB_ACTIONS").is_ok() || zig_found) {
-        cli.push("--zig");
+        cli.push("--zig".into());
         true
     } else {
-        cli.push("--compatibility");
-        cli.push("linux");
+        cli.push("--compatibility".into());
+        cli.push("linux".into());
         false
     };
 
@@ -80,12 +80,10 @@ pub fn test_integration(
         .join("venvs");
     let cffi_provider = "cffi-provider";
     let cffi_venv = venvs_dir.join(cffi_provider);
-    let target_triple = Target::from_target_triple(None)?;
-    let python = target_triple.get_venv_python(&cffi_venv);
 
     if let Some(interp) = python_interp.as_ref() {
-        cli.push("--interpreter");
-        cli.push(interp);
+        cli.push("--interpreter".into());
+        cli.push(interp.into());
     } else {
         // Install cffi in a separate environment
 
@@ -93,8 +91,10 @@ pub fn test_integration(
         // modifies it at a time and that during that time, no other test reads it.
         let file = File::create(venvs_dir.join("cffi-provider.lock"))?;
         file.lock_exclusive()?;
-        if !python.is_file() {
+        let python = if !cffi_venv.is_dir() {
             create_named_virtualenv(cffi_provider, python_interp.clone().map(PathBuf::from))?;
+            let target_triple = Target::from_target_triple(None)?;
+            let python = target_triple.get_venv_python(&cffi_venv);
             assert!(python.is_file(), "cffi venv not created correctly");
             let pip_install_cffi = [
                 "-m",
@@ -118,14 +118,14 @@ pub fn test_integration(
                     stderr
                 );
             }
-        }
-        file.unlock()?;
-        cli.push("--interpreter");
-        cli.push(
             python
-                .to_str()
-                .context("non-utf8 python interpreter path")?,
-        );
+        } else {
+            let target_triple = Target::from_target_triple(None)?;
+            target_triple.get_venv_python(&cffi_venv)
+        };
+        file.unlock()?;
+        cli.push("--interpreter".into());
+        cli.push(python.as_os_str().to_owned());
     }
 
     let options: BuildOptions = BuildOptions::try_parse_from(cli)?;
@@ -239,20 +239,20 @@ pub fn test_integration_conda(package: impl AsRef<Path>, bindings: Option<String
     }
 
     // The first argument is ignored by clap
-    let mut cli = vec![
-        "build",
-        "--manifest-path",
-        &package_string,
-        "--quiet",
-        "--interpreter",
+    let mut cli: Vec<std::ffi::OsString> = vec![
+        "build".into(),
+        "--manifest-path".into(),
+        package_string.into(),
+        "--quiet".into(),
+        "--interpreter".into(),
     ];
     for interp in &interpreters {
-        cli.push(interp.to_str().unwrap());
+        cli.push(interp.to_str().unwrap().into());
     }
 
     if let Some(ref bindings) = bindings {
-        cli.push("--bindings");
-        cli.push(bindings);
+        cli.push("--bindings".into());
+        cli.push(bindings.into());
     }
 
     let options = BuildOptions::try_parse_from(cli)?;