diff --git a/include/ardix/mutex.h b/include/ardix/mutex.h
index 8800e74..a3edcc3 100644
--- a/include/ardix/mutex.h
+++ b/include/ardix/mutex.h
@@ -4,6 +4,7 @@
 
 #include <ardix/types.h>
 
+#include <errno.h>
 #include <toolchain.h>
 
 /**
@@ -73,14 +74,17 @@ __always_inline void mutex_unlock(struct mutex *mutex)
 
 /**
  * @brief Attempt to acquire an exclusive lock on a mutex.
- * The return value is zero if the claim succeeds, and nonzero otherwise.
+ * The return value is zero if the claim succeeds.
  *
  * @param mutex Mutex to attempt to lock
- * @returns 0 if the lock was acquired, a nonzero value otherwise
+ * @returns 0 if the lock was acquired, `-EAGAIN` otherwise
  */
 __always_inline int mutex_trylock(struct mutex *mutex)
 {
-	return _mutex_trylock(&mutex->lock);
+	if (_mutex_trylock(&mutex->lock) == 0)
+		return 0;
+	else
+		return -EAGAIN;
 }
 
 /**
diff --git a/kernel/fs/file.c b/kernel/fs/file.c
index 22d1cab..dbfbe4d 100644
--- a/kernel/fs/file.c
+++ b/kernel/fs/file.c
@@ -84,27 +84,31 @@ void file_put(struct file *f)
 
 ssize_t file_read(void *buf, struct file *file, size_t len)
 {
-	ssize_t ret;
-	mutex_lock(&file->lock);
+	ssize_t ret = mutex_trylock(&file->lock);
 
-	ret = file->device->read(buf, file->device, len, file->pos);
-	if (file->type == FILE_TYPE_REGULAR && ret > 0)
-		file->pos += ret;
+	if (ret == 0) {
+		ret = file->device->read(buf, file->device, len, file->pos);
+		if (file->type == FILE_TYPE_REGULAR && ret > 0)
+			file->pos += ret;
+
+		mutex_unlock(&file->lock);
+	}
 
-	mutex_unlock(&file->lock);
 	return ret;
 }
 
 ssize_t file_write(struct file *file, const void *buf, size_t len)
 {
-	ssize_t ret;
-	mutex_lock(&file->lock);
+	ssize_t ret = mutex_trylock(&file->lock);
 
-	ret = file->device->write(file->device, buf, len, file->pos);
-	if (file->type == FILE_TYPE_REGULAR && ret > 0)
-		file->pos += ret;
+	if (ret == 0) {
+		ret = file->device->write(file->device, buf, len, file->pos);
+		if (file->type == FILE_TYPE_REGULAR && ret > 0)
+			file->pos += ret;
+
+		mutex_unlock(&file->lock);
+	}
 
-	mutex_unlock(&file->lock);
 	return ret;
 }
 
diff --git a/kernel/serial.c b/kernel/serial.c
index b81e299..0c8fd6d 100644
--- a/kernel/serial.c
+++ b/kernel/serial.c
@@ -16,11 +16,13 @@ static ssize_t serial_device_read(void *dest, struct device *dev, size_t len, of
 {
 	ssize_t ret;
 	struct serial_device *serial_dev = container_of(dev, struct serial_device, device);
-	mutex_lock(&dev->lock);
 
-	ret = serial_read(dest, serial_dev, len);
+	ret = mutex_trylock(&dev->lock);
+	if (ret == 0) {
+		ret = serial_read(dest, serial_dev, len);
+		mutex_unlock(&dev->lock);
+	}
 
-	mutex_unlock(&dev->lock);
 	return ret;
 }
 
@@ -28,11 +30,13 @@ static ssize_t serial_device_write(struct device *dev, const void *src, size_t l
 {
 	ssize_t ret;
 	struct serial_device *serial_dev = container_of(dev, struct serial_device, device);
-	mutex_lock(&dev->lock);
 
-	ret = serial_write(serial_dev, src, len);
+	ret = mutex_trylock(&dev->lock);
+	if (ret == 0) {
+		ret = serial_write(serial_dev, src, len);
+		mutex_unlock(&dev->lock);
+	}
 
-	mutex_unlock(&dev->lock);
 	return ret;
 }