diff --git a/flake.nix b/flake.nix
index bd8ad4f..50a4694 100644
--- a/flake.nix
+++ b/flake.nix
@@ -29,12 +29,10 @@
             checkInputs = [ (pkgs.python3.withPackages(ps: [ ps.numpy ps.scipy ])) ];
             checkPhase =
               ''
-              echo "Checking nac3standalone demos..."
+              echo "Running Cargo tests..."
               pushd nac3standalone/demo
               patchShebangs .
-              ./check_demos.sh
               popd
-              echo "Running Cargo tests..."
               cargoCheckHook
               '';
             installPhase =
diff --git a/nac3standalone/src/main.rs b/nac3standalone/src/main.rs
index f34f55a..55c49e3 100644
--- a/nac3standalone/src/main.rs
+++ b/nac3standalone/src/main.rs
@@ -34,6 +34,9 @@ mod basic_symbol_resolver;
 use basic_symbol_resolver::*;
 use nac3core::toplevel::composer::ComposerConfig;
 
+#[cfg(test)]
+mod test;
+
 /// Command-line argument parser definition.
 #[derive(Parser)]
 #[command(author, version, about, long_about = None)]
diff --git a/nac3standalone/src/test.rs b/nac3standalone/src/test.rs
new file mode 100644
index 0000000..2bb5e28
--- /dev/null
+++ b/nac3standalone/src/test.rs
@@ -0,0 +1,148 @@
+use std::fs;
+use std::io;
+use std::path::{Path, PathBuf};
+use std::process::{Command, Output};
+use parking_lot::Mutex;
+
+/// [Mutex] for enforcing only a single `./run_demo.sh` is executing.
+///
+/// This is necessary as the command will generate temporary files (specifically `*.o`, `*.bc`, and
+/// `demo`) in the filesystem.
+static RUN_EXEC_MTX: Mutex<()> = Mutex::new(());
+
+/// Dummy struct for automatically removing temporary files after test case execution completes.
+struct CleanupDemoTempFiles;
+
+impl Default for CleanupDemoTempFiles {
+
+    fn default() -> Self {
+        CleanupDemoTempFiles {}
+    }
+}
+
+impl Drop for CleanupDemoTempFiles {
+
+    fn drop(&mut self) {
+        get_demo_dir().read_dir()
+            .unwrap()
+            .into_iter()
+            .map(|dir_entry| dir_entry.unwrap().path().into_boxed_path())
+            .filter(|p| {
+                let ext = p.extension()
+                    .and_then(|ext| ext.to_str())
+                    .unwrap_or_default();
+                let file_name = p.file_name()
+                    .and_then(|ext| ext.to_str())
+                    .unwrap_or_default();
+
+                ["bc", "o"].contains(&ext) || file_name == "demo"
+            })
+            .for_each(|p| fs::remove_file(p).unwrap())
+    }
+}
+
+/// Returns the absolute [Path] to the `demo` directory.
+fn get_demo_dir() -> PathBuf {
+    std::env::current_dir()
+        .map(|p| p.join("demo"))
+        .and_then(|p| p.canonicalize())
+        .unwrap()
+}
+
+/// Collects all Python tests from `demo/src`.
+fn collect_demo_tests() -> Vec<PathBuf> {
+    get_demo_dir()
+        .join("src")
+        .read_dir()
+        .unwrap()
+        .into_iter()
+        .filter_map(|dir_entry| {
+            let p = dir_entry.unwrap().path();
+
+            if p.is_file() && p.extension().and_then(|ext| ext.to_str()).unwrap_or_default() == "py" {
+                Some(p)
+            } else {
+                None
+            }
+        })
+        .collect()
+}
+
+/// Runs the interpreter on the `file` as if by invoking `interpret_demo.py`.
+fn run_interpreter(file: &Path) -> io::Result<Output> {
+    Command::new("./interpret_demo.py")
+        .arg(file.to_str().unwrap())
+        .current_dir(get_demo_dir())
+        .output()
+}
+
+/// Runs NAC3 on the `file` as if by invoking `run_demo.sh`.
+fn run_demo(file: &Path, nac3_args: &[&str]) -> io::Result<Output> {
+    let _lk = RUN_EXEC_MTX.lock();
+
+    Command::new("./run_demo.sh")
+        .args(nac3_args)
+        .arg(file.to_str().unwrap())
+        .current_dir(get_demo_dir())
+        .output()
+}
+
+#[test]
+fn test_demos_optimized() {
+    let _cleanup = CleanupDemoTempFiles::default();
+
+    let tests = collect_demo_tests();
+
+    for test in tests.iter() {
+        let py_interpreted= run_interpreter(test).unwrap();
+        let py_stdout = String::from_utf8(py_interpreted.stdout).unwrap();
+
+        let executed = run_demo(test, &[]).unwrap();
+        let exec_stdout = String::from_utf8(executed.stdout).unwrap();
+        assert_eq!(py_stdout, exec_stdout, "Execution result mismatch for {}", test.file_name().and_then(|p| p.to_str()).unwrap());
+
+        let bc_interpreted = run_demo(test, &["--lli"]).unwrap();
+        let bc_stdout = String::from_utf8(bc_interpreted.stdout).unwrap();
+        assert_eq!(py_stdout, bc_stdout, "Execution result mismatch for {}", test.file_name().and_then(|p| p.to_str()).unwrap());
+    }
+}
+
+#[test]
+fn test_demos_unoptimized() {
+    let _cleanup = CleanupDemoTempFiles::default();
+
+    let tests = collect_demo_tests();
+
+    for test in tests.iter() {
+        let py_interpreted= run_interpreter(test).unwrap();
+        let py_stdout = String::from_utf8(py_interpreted.stdout).unwrap();
+
+        let executed = run_demo(test, &["-O0"]).unwrap();
+        let exec_stdout = String::from_utf8(executed.stdout).unwrap();
+        assert_eq!(py_stdout, exec_stdout, "Execution result differs for {}", test.file_name().and_then(|p| p.to_str()).unwrap());
+
+        let bc_interpreted= run_demo(test, &["--lli", "-O0"]).unwrap();
+        let bc_stdout = String::from_utf8(bc_interpreted.stdout).unwrap();
+        assert_eq!(py_stdout, bc_stdout, "Execution result mismatch for {}", test.file_name().and_then(|p| p.to_str()).unwrap());
+    }
+}
+
+#[test]
+fn test_demos_multithreaded() {
+    let _cleanup = CleanupDemoTempFiles::default();
+
+    let tests = collect_demo_tests();
+
+    for test in tests.iter() {
+        let py_interpreted= run_interpreter(test).unwrap();
+        let py_stdout = String::from_utf8(py_interpreted.stdout).unwrap();
+
+        let executed = run_demo(test, &["-T4"]).unwrap();
+        let exec_stdout = String::from_utf8(executed.stdout).unwrap();
+        assert_eq!(py_stdout, exec_stdout, "Execution result differs for {}", test.file_name().and_then(|p| p.to_str()).unwrap());
+
+        let bc_interpreted= run_demo(test, &["--lli", "-T4"]).unwrap();
+        let bc_stdout = String::from_utf8(bc_interpreted.stdout).unwrap();
+        assert_eq!(py_stdout, bc_stdout, "Execution result mismatch for {}", test.file_name().and_then(|p| p.to_str()).unwrap());
+    }
+}
\ No newline at end of file