diff --git a/src/combineProducers.lua b/src/combineProducers.lua
index e7fc5ec..4509169 100644
--- a/src/combineProducers.lua
+++ b/src/combineProducers.lua
@@ -30,15 +30,18 @@ local function combineActions(producers: types.ProducerMap)
 
 	for actionName, actions in actionsByName do
 		combinedActions[actionName] = function(combinedState, ...)
-			local nextState = table.clone(combinedState)
+			local nextState
 
 			for _, action in actions do
 				local producerName = producerNamesByAction[action]
-				local producerState = nextState[producerName]
-				nextState[producerName] = action(producerState, ...)
+				local producerState = combinedState[producerName]
+				local newState = action(producerState, ...)
+				if newState == producerState then continue end
+				if not nextState then nextState = table.clone(combinedState) end
+				nextState[producerName] = newState
 			end
 
-			return nextState
+			return nextState or combinedState
 		end
 	end
 
diff --git a/src/utils/createSelectArrayDiffs.lua b/src/utils/createSelectArrayDiffs.lua
index 152ec57..9e4d976 100644
--- a/src/utils/createSelectArrayDiffs.lua
+++ b/src/utils/createSelectArrayDiffs.lua
@@ -37,17 +37,19 @@ local function createSelectArrayDiffs<State, K, V>(
 		local deletions: { Entry<K, V> } = {}
 		local entries: { [unknown]: Entry<K, V> } = {}
 
-		for key, item in items do
-			local id = if discriminator then discriminator(item, key) else item
-			local entry = { key = key, value = item, id = id }
+		if items then
+			for key, item in items do
+				local id = if discriminator then discriminator(item, key) else item
+				local entry = { key = key, value = item, id = id }
 
-			assert(id ~= nil, "Discriminator returned a nil value")
+				assert(id ~= nil, "Discriminator returned a nil value")
 
-			if not lastEntries[id] then
-				table.insert(additions, entry)
-			end
+				if not lastEntries[id] then
+					table.insert(additions, entry)
+				end
 
-			entries[id] = entry
+				entries[id] = entry
+			end
 		end
 
 		for id, item in lastEntries do