diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
index f14d372..e0f4e9f 100644
--- a/.github/workflows/test.yaml
+++ b/.github/workflows/test.yaml
@@ -12,6 +12,7 @@ jobs:
     continue-on-error: ${{matrix.experimental}}
     
     strategy:
+      fail-fast: false
       matrix:
         os:
           - ubuntu
diff --git a/ext/cool.io/watcher.h b/ext/cool.io/watcher.h
index b4892f2..f795d28 100644
--- a/ext/cool.io/watcher.h
+++ b/ext/cool.io/watcher.h
@@ -26,20 +26,15 @@
 
 #define Watcher_Detach(watcher_type, watcher) \
   struct Coolio_Watcher *watcher_data; \
-  struct Coolio_Loop *loop_data; \
   \
   watcher_data = Coolio_Watcher_ptr(watcher); \
   \
   if(watcher_data->loop == Qnil) \
     rb_raise(rb_eRuntimeError, "not attached to a loop"); \
   \
-  if (watcher_data->enabled == 0) { \
-    /* Ignore because watcher was already detached. */ \
-    return Qnil; \
+  if (watcher_data->enabled) { \
+    rb_funcall(watcher, rb_intern("disable"), 0); \
   } \
-  loop_data = Coolio_Loop_ptr(watcher_data->loop); \
-  \
-  ev_##watcher_type##_stop(loop_data->ev_loop, &watcher_data->event_types.ev_##watcher_type); \
   rb_call_super(0, 0)
 
 #define Watcher_Enable(watcher_type, watcher) \
@@ -66,10 +61,10 @@
   if(watcher_data->loop == Qnil) \
     rb_raise(rb_eRuntimeError, "not attached to a loop"); \
   \
-  rb_call_super(0, 0); \
-  \
-  loop_data = Coolio_Loop_ptr(watcher_data->loop); \
-  \
-  ev_##watcher_type##_stop(loop_data->ev_loop, &watcher_data->event_types.ev_##watcher_type)
+  if (watcher_data->enabled) { \
+    loop_data = Coolio_Loop_ptr(watcher_data->loop); \
+    ev_##watcher_type##_stop(loop_data->ev_loop, &watcher_data->event_types.ev_##watcher_type); \
+  } \
+  rb_call_super(0, 0);
 
 #endif
diff --git a/spec/detach_race_condition_spec.rb b/spec/detach_race_condition_spec.rb
index b22970c..5d11be2 100644
--- a/spec/detach_race_condition_spec.rb
+++ b/spec/detach_race_condition_spec.rb
@@ -47,4 +47,49 @@ def on_readable
       end
     }.not_to raise_error
   end
+
+  class HttpHandler < Coolio::IO
+    RESPONSE = "HTTP/1.1 200 OK\r\nContent-Length: 1024\r\nConnection: close\r\n\r\n" + ("X" * 1024)
+
+    def on_connect
+    end
+
+    def on_read(data)
+      write(RESPONSE)
+    end
+
+    def on_write_complete
+      close
+    end
+  end
+
+  # https://github.com/socketry/cool.io/issues/89
+  it "does not cause memory leaks" do
+    port = 18989
+    loop = Coolio::Loop.default
+
+    server = Coolio::TCPServer.new('127.0.0.1', port, HttpHandler)
+    server.attach(loop)
+
+    event_thread = Thread.new { loop.run }
+
+    request = "GET / HTTP/1.1\r\nHost: localhost\r\n\r\n"
+
+    10.times do |iteration|
+      begin
+        sock = TCPSocket.new('127.0.0.1', port)
+        sock.write(request)
+        sock.read
+        sock.close
+      rescue => e
+        sleep 0.01
+        retry
+      end
+    end
+
+    server.close
+    event_thread.join
+
+    expect(loop.watchers).to be_empty
+  end
 end