diff --git a/src/futex.rs b/src/futex.rs
index 25df6f5..f0a15f9 100644
--- a/src/futex.rs
+++ b/src/futex.rs
@@ -132,4 +132,49 @@ mod tests {
             task.join().unwrap();
         }
     }
+
+    #[test]
+    fn test_concurrent() {
+        let lock = Arc::new(Mutex::new());
+        let counter = Arc::new(AtomicU32::new(0));
+        const THREAD_COUNT: usize = 4;
+        const ITERATIONS: usize = 10000;
+
+        let mut handles = vec![];
+
+        // Spawn multiple threads that increment and decrement a shared counter
+        for _ in 0..THREAD_COUNT {
+            let lock = Arc::clone(&lock);
+            let counter = Arc::clone(&counter);
+
+            handles.push(std::thread::spawn(move || {
+                for _ in 0..ITERATIONS {
+                    // Lock and modify shared state
+                    lock.lock();
+                    let value = counter.load(Relaxed);
+                    std::thread::yield_now(); // Force a context switch to increase contention
+                    counter.store(value + 1, Relaxed);
+                    lock.unlock();
+
+                    // Do some work without the lock
+                    std::thread::yield_now();
+
+                    // Lock and modify shared state again
+                    lock.lock();
+                    let value = counter.load(Relaxed);
+                    std::thread::yield_now(); // Force a context switch to increase contention
+                    counter.store(value - 1, Relaxed);
+                    lock.unlock();
+                }
+            }));
+        }
+
+        // Wait for all threads to complete
+        for handle in handles {
+            handle.join().unwrap();
+        }
+
+        // Verify the final counter value is 0
+        assert_eq!(counter.load(Relaxed), 0);
+    }
 }
diff --git a/src/lockmap.rs b/src/lockmap.rs
index c264bc6..cbf9098 100644
--- a/src/lockmap.rs
+++ b/src/lockmap.rs
@@ -886,4 +886,50 @@ mod tests {
         set_thread.join().unwrap();
         get_thread.join().unwrap();
     }
+
+    #[test]
+    fn test_lockmap_heavy_contention() {
+        let lock_map = Arc::new(LockMap::<u32, u32>::new());
+        const THREADS: usize = 16;
+        const OPS_PER_THREAD: usize = 10000;
+        const HOT_KEYS: u32 = 5;
+
+        let counter = Arc::new(AtomicU32::new(0));
+
+        let threads: Vec<_> = (0..THREADS)
+            .map(|_| {
+                let lock_map = lock_map.clone();
+                let counter = counter.clone();
+                std::thread::spawn(move || {
+                    for _ in 0..OPS_PER_THREAD {
+                        let key = rand::random::<u32>() % HOT_KEYS;
+                        let mut entry = lock_map.entry(key);
+
+                        // Simulate some work
+                        std::thread::sleep(std::time::Duration::from_nanos(10));
+
+                        match entry.get_mut() {
+                            Some(value) => {
+                                *value = value.wrapping_add(1);
+                                counter.fetch_add(1, Ordering::Relaxed);
+                            }
+                            None => {
+                                entry.insert(1);
+                                counter.fetch_add(1, Ordering::Relaxed);
+                            }
+                        }
+                    }
+                })
+            })
+            .collect();
+
+        for thread in threads {
+            thread.join().unwrap();
+        }
+
+        assert_eq!(
+            counter.load(Ordering::Relaxed),
+            THREADS as u32 * OPS_PER_THREAD as u32
+        );
+    }
 }