diff --git a/src/backend/KQueue.zig b/src/backend/KQueue.zig
index a8f6d4d..77e8aed 100644
--- a/src/backend/KQueue.zig
+++ b/src/backend/KQueue.zig
@@ -274,6 +274,12 @@ fn register_file_watch(self: *@This(), allocator: std.mem.Allocator, path: []con
         return;
     };
     self.file_watches_mutex.lock();
+    if (self.file_watches.contains(path)) {
+        self.file_watches_mutex.unlock();
+        std.posix.close(fd);
+        allocator.free(owned);
+        return;
+    }
     self.file_watches.put(allocator, owned, fd) catch {
         self.file_watches_mutex.unlock();
         std.posix.close(fd);
@@ -350,6 +356,12 @@ pub fn add_watch(self: *@This(), allocator: std.mem.Allocator, path: []const u8)
     };
     const owned_path = try allocator.dupe(u8, path);
     self.watches_mutex.lock();
+    if (self.watches.contains(path)) {
+        self.watches_mutex.unlock();
+        std.posix.close(path_fd);
+        allocator.free(owned_path);
+        return;
+    }
     self.watches.put(allocator, owned_path, path_fd) catch |e| {
         self.watches_mutex.unlock();
         allocator.free(owned_path);
diff --git a/src/backend/KQueueDir.zig b/src/backend/KQueueDir.zig
index 8908ec0..6bbf770 100644
--- a/src/backend/KQueueDir.zig
+++ b/src/backend/KQueueDir.zig
@@ -315,6 +315,12 @@ pub fn add_watch(self: *@This(), allocator: std.mem.Allocator, path: []const u8)
     const is_file = if (stat) |s| std.posix.S.ISREG(s.mode) else false;
     const owned_path = try allocator.dupe(u8, path);
     self.watches_mutex.lock();
+    if (self.watches.contains(path)) {
+        self.watches_mutex.unlock();
+        std.posix.close(path_fd);
+        allocator.free(owned_path);
+        return;
+    }
     self.watches.put(allocator, owned_path, .{ .fd = path_fd, .is_file = is_file }) catch |e| {
         self.watches_mutex.unlock();
         allocator.free(owned_path);