diff --git a/addons/ob.luau b/addons/ob.luau
index 6b20c58..6661c47 100755
--- a/addons/ob.luau
+++ b/addons/ob.luau
@@ -12,6 +12,10 @@ export type Iter<T...> = (Observer<T...>) -> () -> (jecs.Entity, T...)
 
 export type Observer<T...> = {
 	disconnect: (Observer<T...>) -> (),
+}
+
+export type Monitor<T...> = {
+	disconnect: (Observer<T...>) -> (),
 	added: ((jecs.Entity) -> ()) -> (),
 	removed: ((jecs.Entity) -> ()) -> ()
 }
@@ -77,11 +81,11 @@ local function observers_new<T...>(
    	if without then
 		for _, term in without do
 			if jecs.IS_PAIR(term) then
-				local rel = jecs.ECS_PAIR_SECOND(term)
+				local rel = jecs.ECS_PAIR_FIRST(term)
 				local tgt = jecs.ECS_PAIR_SECOND(term)
 				local wc = tgt == jecs.w
 				local onremoved = world:removed(rel, function(entity, id)
-					if not wc and term ~= tgt then
+					if not wc and id ~= term then
 						return
 					end
 					local r = jecs.record(world, entity)
@@ -137,7 +141,7 @@ local function observers_new<T...>(
     return (observer :: any) :: Observer<T...>
 end
 
-local function monitors_new<T...>(query: Query<T...>): Observer<T...>
+local function monitors_new<T...>(query: Query<T...>): Monitor<T...>
 	query:cached()
 
 	local world = (query :: Query<T...> & { world: World }).world
@@ -313,7 +317,7 @@ local function monitors_new<T...>(query: Query<T...>): Observer<T...>
      	removed = monitor_removed
    	}
 
-    return (observer :: any) :: Observer<T...>
+    return (observer :: any) :: Monitor<T...>
 end
 
 return {
diff --git a/test/addons/ob.luau b/test/addons/ob.luau
index 00d2e1d..fbe0ccd 100755
--- a/test/addons/ob.luau
+++ b/test/addons/ob.luau
@@ -5,7 +5,203 @@ local CASE, TEST, FINISH, CHECK = test.CASE, test.TEST, test.FINISH, test.CHECK
 local FOCUS = test.FOCUS
 local ob = require("@addons/ob")
 
-TEST("addons/ob", function()
+TEST("addons/ob::observer", function()
+	local world = jecs.world()
+	do CASE "should match against archetypes that were already created"
+		local A = world:component()
+
+		local e1 = world:entity()
+		world:add(e1, A)
+
+		local c = 1
+		ob.observer(world:query(A), function()
+			c+=1
+		end)
+
+		world:remove(e1, A)
+		world:add(e1, A)
+		CHECK(c==2)
+	end
+
+	do CASE "Should enter observer at query:without(pair(R, t1)) when adding pair(R, t2)"
+		local A = world:component()
+		local B = world:component()
+		local C = world:component()
+		local D = world:component()
+
+		local e = world:entity()
+		world:add(e, A)
+		world:add(e, jecs.pair(B, D))
+
+		local c = 1
+
+		ob.observer(world:query(A):without(jecs.pair(B, C)), function()
+			c += 1
+		end)
+
+		local child = world:entity()
+		world:add(child, A)
+		CHECK(c==2)
+		world:add(child, jecs.pair(B, D))
+		CHECK(c==2)
+		world:add(child, jecs.pair(B, C))
+		CHECK(c==2)
+	end
+
+	do CASE "Should enter observer at query:without(pair(R, t1)) when removing pair(R, t1)"
+		local A = world:component()
+		local B = world:component()
+		local C = world:component()
+		local D = world:component()
+
+		local e = world:entity()
+		world:add(e, A)
+		world:add(e, jecs.pair(B, D))
+
+		local c = 1
+		ob.observer(world:query(A):without(jecs.pair(B, D)), function()
+			c += 1
+		end)
+
+		local child = world:entity()
+		world:add(child, jecs.pair(B, C))
+		world:add(child, jecs.pair(B, D))
+		CHECK(c==1)
+		world:add(child, A)
+		CHECK(c==1)
+		world:remove(child, jecs.pair(B, C))
+		CHECK(c==1)
+		world:add(child, jecs.pair(B, C))
+		CHECK(c==1)
+		world:remove(child, jecs.pair(B, D))
+		CHECK(c==2)
+		world:add(child, jecs.pair(B, D))
+		CHECK(c==2)
+		world:remove(child, jecs.pair(B, C))
+		CHECK(c==2)
+		world:remove(child, jecs.pair(B, D))
+		CHECK(c==3)
+	end
+
+	do CASE "Should enter observer at query:without(pair(R, *)) when adding pair(R, t1)"
+		local A = world:component()
+		local B = world:component()
+		local C = world:component()
+		local D = world:component()
+
+		local c = 1
+		ob.observer(world:query(A):without(jecs.pair(B, jecs.w)), function() c+= 1 end)
+
+		local child = world:entity()
+		world:add(child, A)
+		CHECK(c==2)
+		world:add(child, jecs.pair(B, D))
+		CHECK(c==2)
+		world:add(child, jecs.pair(B, C))
+		CHECK(c==2)
+	end
+
+	do CASE "Should enter observer at query:without(t1) when removing t1"
+		local A = world:component()
+		local B = world:component()
+
+		local c = 1
+		ob.observer(world:query(A):without(B), function() c+= 1 end)
+
+		local child = world:entity()
+		world:add(child, B)
+		CHECK(c==1)
+		world:add(child, A)
+		CHECK(c==1)
+		world:remove(child, B)
+		CHECK(c==2)
+		world:remove(child, A)
+		CHECK(c==2)
+	end
+
+	do CASE "observers should accept pairs"
+		local A = world:component()
+		local B = world:component()
+
+		local c = 1
+		ob.observer(world:query(jecs.pair(A, B)), function() c+= 1 end)
+
+		local child = world:entity()
+		world:add(child, jecs.pair(A, B))
+		CHECK(c == 2)
+
+		world:remove(child, jecs.pair(A, B))
+		CHECK(c == 2)
+	end
+
+	do CASE "Ensure ordering between signals and observers"
+		local A = world:component()
+		local B = world:component()
+
+		local count = 1
+		local function counter()
+			count += 1
+		end
+
+		ob.observer(world:query(A, B), counter)
+
+		world:added(A, counter)
+		world:added(A, counter)
+
+		for _ in world:query(A) do
+
+		end
+
+		local e = world:entity()
+		world:add(e, A)
+		CHECK(count == 3)
+
+		world:add(e, B)
+		CHECK(count == 4)
+	end
+
+	do CASE "Rematch entities in observers"
+		local A = world:component()
+
+		local count = 1
+		local function counter()
+			count += 1
+		end
+
+		ob.observer(world:query(A), counter)
+
+		local e = world:entity()
+		world:set(e, A, false)
+		CHECK(count == 2)
+		world:remove(e, A)
+		CHECK(count == 2)
+		world:set(e, A, false)
+		CHECK(count == 3)
+		world:set(e, A, false)
+		CHECK(count == 4)
+	end
+
+	do CASE "Call off pairs"
+		local A = world:component()
+
+		local callcount = 1
+		world:added(A, function(entity)
+			callcount += 1
+		end)
+		world:added(A, function(entity)
+			callcount += 1
+		end)
+
+		local e = world:entity()
+		local e2 = world:entity()
+
+		world:add(e2, jecs.pair(A, e))
+		world:add(e, jecs.pair(A, e2))
+		CHECK(callcount == 1 + 2 * 2)
+	end
+end)
+
+TEST("addons/ob::monitor", function()
 	local world = jecs.world()
 	do CASE "should match against archetypes that were already created"
 		local A = world:component()
@@ -61,8 +257,6 @@ TEST("addons/ob", function()
 		local C = world:component()
 		local D = world:component()
 
-		print("B", B)
-
 		local e = world:entity()
 		world:add(e, A)
 		world:add(e, jecs.pair(B, D))
@@ -172,53 +366,6 @@ TEST("addons/ob", function()
 		CHECK(c == 3)
 	end
 
-	do CASE "Ensure ordering between signals and observers"
-		local A = world:component()
-		local B = world:component()
-
-		local count = 1
-		local function counter()
-			count += 1
-		end
-
-		ob.observer(world:query(A, B), counter)
-
-		world:added(A, counter)
-		world:added(A, counter)
-
-		for _ in world:query(A) do
-
-		end
-
-		local e = world:entity()
-		world:add(e, A)
-		CHECK(count == 3)
-
-		world:add(e, B)
-		CHECK(count == 4)
-	end
-
-	do CASE "Rematch entities in observers"
-		local A = world:component()
-
-		local count = 1
-		local function counter()
-			count += 1
-		end
-
-		ob.observer(world:query(A), counter)
-
-		local e = world:entity()
-		world:set(e, A, false)
-		CHECK(count == 2)
-		world:remove(e, A)
-		CHECK(count == 2)
-		world:set(e, A, false)
-		CHECK(count == 3)
-		world:set(e, A, false)
-		CHECK(count == 4)
-	end
-
 	do CASE "Don't report changed components in monitor"
 		local A = world:component()
 		local count = 1
@@ -240,25 +387,6 @@ TEST("addons/ob", function()
 		world:set(e, A, false)
 		CHECK(count == 4)
 	end
-
-	do CASE "Call off pairs"
-		local A = world:component()
-
-		local callcount = 1
-		world:added(A, function(entity)
-			callcount += 1
-		end)
-		world:added(A, function(entity)
-			callcount += 1
-		end)
-
-		local e = world:entity()
-		local e2 = world:entity()
-
-		world:add(e2, jecs.pair(A, e))
-		world:add(e, jecs.pair(A, e2))
-		CHECK(callcount == 1 + 2 * 2)
-	end
 end)
 
 return FINISH()