diff --git a/app/Generator/Chart/Account/AccountChartGeneratorInterface.php b/app/Generator/Chart/Account/AccountChartGeneratorInterface.php
index c8379d8744..f4e5ba6938 100644
--- a/app/Generator/Chart/Account/AccountChartGeneratorInterface.php
+++ b/app/Generator/Chart/Account/AccountChartGeneratorInterface.php
@@ -29,7 +29,7 @@ interface AccountChartGeneratorInterface
      *
      * @return array
      */
-    public function expenseAccounts(Collection $accounts, Carbon $start, Carbon $end);
+    public function expenseAccounts(Collection $accounts, Carbon $start, Carbon $end): array;
 
     /**
      * @param Collection $accounts
@@ -38,7 +38,7 @@ interface AccountChartGeneratorInterface
      *
      * @return array
      */
-    public function frontpage(Collection $accounts, Carbon $start, Carbon $end);
+    public function frontpage(Collection $accounts, Carbon $start, Carbon $end): array;
 
     /**
      * @param Account $account
@@ -47,5 +47,5 @@ interface AccountChartGeneratorInterface
      *
      * @return array
      */
-    public function single(Account $account, Carbon $start, Carbon $end);
+    public function single(Account $account, Carbon $start, Carbon $end): array;
 }
diff --git a/app/Generator/Chart/Account/ChartJsAccountChartGenerator.php b/app/Generator/Chart/Account/ChartJsAccountChartGenerator.php
index c0cc13aef3..d611ab2ad3 100644
--- a/app/Generator/Chart/Account/ChartJsAccountChartGenerator.php
+++ b/app/Generator/Chart/Account/ChartJsAccountChartGenerator.php
@@ -22,7 +22,7 @@ class ChartJsAccountChartGenerator implements AccountChartGeneratorInterface
      *
      * @return array
      */
-    public function expenseAccounts(Collection $accounts, Carbon $start, Carbon $end)
+    public function expenseAccounts(Collection $accounts, Carbon $start, Carbon $end): array
     {
         $data = [
             'count'  => 1,
@@ -69,7 +69,7 @@ class ChartJsAccountChartGenerator implements AccountChartGeneratorInterface
      *
      * @return array
      */
-    public function frontpage(Collection $accounts, Carbon $start, Carbon $end)
+    public function frontpage(Collection $accounts, Carbon $start, Carbon $end): array
     {
         // language:
         $format  = (string)trans('config.month_and_day');
@@ -116,7 +116,7 @@ class ChartJsAccountChartGenerator implements AccountChartGeneratorInterface
      *
      * @return array
      */
-    public function single(Account $account, Carbon $start, Carbon $end)
+    public function single(Account $account, Carbon $start, Carbon $end): array
     {
         // language:
         $format = (string)trans('config.month_and_day');
@@ -153,7 +153,7 @@ class ChartJsAccountChartGenerator implements AccountChartGeneratorInterface
      *
      * @return array
      */
-    protected function getIdsFromCollection(Collection $collection)
+    protected function getIdsFromCollection(Collection $collection): array
     {
         $ids = [];
         foreach ($collection as $entry) {
@@ -170,7 +170,7 @@ class ChartJsAccountChartGenerator implements AccountChartGeneratorInterface
      *
      * @return string
      */
-    protected function isInArray($array, $entryId)
+    protected function isInArray($array, $entryId): string
     {
         if (isset($array[$entryId])) {
             return $array[$entryId];
diff --git a/app/Generator/Chart/Bill/BillChartGeneratorInterface.php b/app/Generator/Chart/Bill/BillChartGeneratorInterface.php
index 4f0b36dded..1baa03cc3e 100644
--- a/app/Generator/Chart/Bill/BillChartGeneratorInterface.php
+++ b/app/Generator/Chart/Bill/BillChartGeneratorInterface.php
@@ -28,7 +28,7 @@ interface BillChartGeneratorInterface
      *
      * @return array
      */
-    public function frontpage(string $paid, string $unpaid);
+    public function frontpage(string $paid, string $unpaid): array;
 
     /**
      * @param Bill       $bill
@@ -36,6 +36,6 @@ interface BillChartGeneratorInterface
      *
      * @return array
      */
-    public function single(Bill $bill, Collection $entries);
+    public function single(Bill $bill, Collection $entries): array;
 
 }
diff --git a/app/Generator/Chart/Bill/ChartJsBillChartGenerator.php b/app/Generator/Chart/Bill/ChartJsBillChartGenerator.php
index 3dbea5f630..f81362c1b4 100644
--- a/app/Generator/Chart/Bill/ChartJsBillChartGenerator.php
+++ b/app/Generator/Chart/Bill/ChartJsBillChartGenerator.php
@@ -28,7 +28,7 @@ class ChartJsBillChartGenerator implements BillChartGeneratorInterface
      *
      * @return array
      */
-    public function frontpage(string $paid, string $unpaid)
+    public function frontpage(string $paid, string $unpaid): array
     {
         bcscale(2);
         $data = [
@@ -55,7 +55,7 @@ class ChartJsBillChartGenerator implements BillChartGeneratorInterface
      *
      * @return array
      */
-    public function single(Bill $bill, Collection $entries)
+    public function single(Bill $bill, Collection $entries): array
     {
         bcscale(2);
         $format       = (string)trans('config.month');
diff --git a/app/Generator/Chart/Budget/BudgetChartGeneratorInterface.php b/app/Generator/Chart/Budget/BudgetChartGeneratorInterface.php
index 3e59760772..fe85f83a70 100644
--- a/app/Generator/Chart/Budget/BudgetChartGeneratorInterface.php
+++ b/app/Generator/Chart/Budget/BudgetChartGeneratorInterface.php
@@ -24,28 +24,28 @@ interface BudgetChartGeneratorInterface
      *
      * @return array
      */
-    public function budget(Collection $entries);
+    public function budget(Collection $entries): array;
 
     /**
      * @param Collection $entries
      *
      * @return array
      */
-    public function budgetLimit(Collection $entries);
+    public function budgetLimit(Collection $entries): array;
 
     /**
      * @param Collection $entries
      *
      * @return array
      */
-    public function frontpage(Collection $entries);
+    public function frontpage(Collection $entries): array;
 
     /**
      * @param Collection $entries
      *
      * @return array
      */
-    public function multiYear(Collection $entries);
+    public function multiYear(Collection $entries): array;
 
     /**
      * @param Collection $budgets
@@ -53,6 +53,6 @@ interface BudgetChartGeneratorInterface
      *
      * @return array
      */
-    public function year(Collection $budgets, Collection $entries);
+    public function year(Collection $budgets, Collection $entries): array;
 
 }
diff --git a/app/Generator/Chart/Budget/ChartJsBudgetChartGenerator.php b/app/Generator/Chart/Budget/ChartJsBudgetChartGenerator.php
index 0bbce5b50b..e5ce03b155 100644
--- a/app/Generator/Chart/Budget/ChartJsBudgetChartGenerator.php
+++ b/app/Generator/Chart/Budget/ChartJsBudgetChartGenerator.php
@@ -21,7 +21,7 @@ class ChartJsBudgetChartGenerator implements BudgetChartGeneratorInterface
      *
      * @return array
      */
-    public function budget(Collection $entries, $dateFormat = 'month')
+    public function budget(Collection $entries, $dateFormat = 'month'): array
     {
         // language:
         $language = Preferences::get('language', env('DEFAULT_LANGUAGE', 'en_US'))->data;
@@ -56,7 +56,7 @@ class ChartJsBudgetChartGenerator implements BudgetChartGeneratorInterface
      *
      * @return array
      */
-    public function budgetLimit(Collection $entries)
+    public function budgetLimit(Collection $entries): array
     {
         return $this->budget($entries, 'monthAndDay');
     }
@@ -66,7 +66,7 @@ class ChartJsBudgetChartGenerator implements BudgetChartGeneratorInterface
      *
      * @return array
      */
-    public function frontpage(Collection $entries)
+    public function frontpage(Collection $entries): array
     {
         bcscale(2);
         $data      = [
@@ -112,7 +112,7 @@ class ChartJsBudgetChartGenerator implements BudgetChartGeneratorInterface
      *
      * @return array
      */
-    public function multiYear(Collection $entries)
+    public function multiYear(Collection $entries): array
     {
         // dataset:
         $data = [
@@ -147,7 +147,7 @@ class ChartJsBudgetChartGenerator implements BudgetChartGeneratorInterface
      *
      * @return array
      */
-    public function year(Collection $budgets, Collection $entries)
+    public function year(Collection $budgets, Collection $entries): array
     {
         // language:
         $format = (string)trans('config.month');
diff --git a/app/Generator/Chart/Category/CategoryChartGeneratorInterface.php b/app/Generator/Chart/Category/CategoryChartGeneratorInterface.php
index 870e3a39fa..c5d0bca4bb 100644
--- a/app/Generator/Chart/Category/CategoryChartGeneratorInterface.php
+++ b/app/Generator/Chart/Category/CategoryChartGeneratorInterface.php
@@ -33,28 +33,28 @@ interface CategoryChartGeneratorInterface
      *
      * @return array
      */
-    public function earnedInPeriod(Collection $categories, Collection $entries);
+    public function earnedInPeriod(Collection $categories, Collection $entries): array;
 
     /**
      * @param Collection $entries
      *
      * @return array
      */
-    public function frontpage(Collection $entries);
+    public function frontpage(Collection $entries): array;
 
     /**
      * @param Collection $entries
      *
      * @return array
      */
-    public function multiYear(Collection $entries);
+    public function multiYear(Collection $entries): array;
 
     /**
      * @param Collection $entries
      *
      * @return array
      */
-    public function period(Collection $entries);
+    public function period(Collection $entries): array;
 
     /**
      * @param Collection $categories
@@ -62,5 +62,5 @@ interface CategoryChartGeneratorInterface
      *
      * @return array
      */
-    public function spentInPeriod(Collection $categories, Collection $entries);
+    public function spentInPeriod(Collection $categories, Collection $entries): array;
 }
diff --git a/app/Generator/Chart/Category/ChartJsCategoryChartGenerator.php b/app/Generator/Chart/Category/ChartJsCategoryChartGenerator.php
index b972718905..9c15606ddd 100644
--- a/app/Generator/Chart/Category/ChartJsCategoryChartGenerator.php
+++ b/app/Generator/Chart/Category/ChartJsCategoryChartGenerator.php
@@ -18,7 +18,7 @@ class ChartJsCategoryChartGenerator implements CategoryChartGeneratorInterface
      *
      * @return array
      */
-    public function all(Collection $entries)
+    public function all(Collection $entries): array
     {
 
 
@@ -55,7 +55,7 @@ class ChartJsCategoryChartGenerator implements CategoryChartGeneratorInterface
      *
      * @return array
      */
-    public function earnedInPeriod(Collection $categories, Collection $entries)
+    public function earnedInPeriod(Collection $categories, Collection $entries): array
     {
 
         // language:
@@ -87,7 +87,7 @@ class ChartJsCategoryChartGenerator implements CategoryChartGeneratorInterface
      *
      * @return array
      */
-    public function frontpage(Collection $entries)
+    public function frontpage(Collection $entries): array
     {
         bcscale(2);
         $data = [
@@ -115,7 +115,7 @@ class ChartJsCategoryChartGenerator implements CategoryChartGeneratorInterface
      *
      * @return array
      */
-    public function multiYear(Collection $entries)
+    public function multiYear(Collection $entries): array
     {
         // dataset:
         $data = [
@@ -155,7 +155,7 @@ class ChartJsCategoryChartGenerator implements CategoryChartGeneratorInterface
      *
      * @return array
      */
-    public function period(Collection $entries)
+    public function period(Collection $entries): array
     {
         return $this->all($entries);
 
@@ -167,7 +167,7 @@ class ChartJsCategoryChartGenerator implements CategoryChartGeneratorInterface
      *
      * @return array
      */
-    public function spentInPeriod(Collection $categories, Collection $entries)
+    public function spentInPeriod(Collection $categories, Collection $entries): array
     {
 
         // language:
diff --git a/app/Generator/Chart/PiggyBank/ChartJsPiggyBankChartGenerator.php b/app/Generator/Chart/PiggyBank/ChartJsPiggyBankChartGenerator.php
index 6951f81eca..c59663b8c9 100644
--- a/app/Generator/Chart/PiggyBank/ChartJsPiggyBankChartGenerator.php
+++ b/app/Generator/Chart/PiggyBank/ChartJsPiggyBankChartGenerator.php
@@ -19,7 +19,7 @@ class ChartJsPiggyBankChartGenerator implements PiggyBankChartGeneratorInterface
      *
      * @return array
      */
-    public function history(Collection $set)
+    public function history(Collection $set): array
     {
 
         // language:
diff --git a/app/Generator/Chart/PiggyBank/PiggyBankChartGeneratorInterface.php b/app/Generator/Chart/PiggyBank/PiggyBankChartGeneratorInterface.php
index fed9e356fd..336bbceb71 100644
--- a/app/Generator/Chart/PiggyBank/PiggyBankChartGeneratorInterface.php
+++ b/app/Generator/Chart/PiggyBank/PiggyBankChartGeneratorInterface.php
@@ -24,5 +24,5 @@ interface PiggyBankChartGeneratorInterface
      *
      * @return array
      */
-    public function history(Collection $set);
+    public function history(Collection $set): array;
 }
diff --git a/app/Generator/Chart/Report/ChartJsReportChartGenerator.php b/app/Generator/Chart/Report/ChartJsReportChartGenerator.php
index a9d969d510..4a4f063d72 100644
--- a/app/Generator/Chart/Report/ChartJsReportChartGenerator.php
+++ b/app/Generator/Chart/Report/ChartJsReportChartGenerator.php
@@ -19,7 +19,7 @@ class ChartJsReportChartGenerator implements ReportChartGeneratorInterface
      *
      * @return array
      */
-    public function multiYearInOut(Collection $entries)
+    public function multiYearInOut(Collection $entries): array
     {
         $data = [
             'count'    => 2,
@@ -52,7 +52,7 @@ class ChartJsReportChartGenerator implements ReportChartGeneratorInterface
      *
      * @return array
      */
-    public function multiYearInOutSummarized(string $income, string $expense, int $count)
+    public function multiYearInOutSummarized(string $income, string $expense, int $count): array
     {
         $data                          = [
             'count'    => 2,
@@ -81,7 +81,7 @@ class ChartJsReportChartGenerator implements ReportChartGeneratorInterface
      *
      * @return array
      */
-    public function yearInOut(Collection $entries)
+    public function yearInOut(Collection $entries): array
     {
         // language:
         $format = (string)trans('config.month');
@@ -117,7 +117,7 @@ class ChartJsReportChartGenerator implements ReportChartGeneratorInterface
      *
      * @return array
      */
-    public function yearInOutSummarized(string $income, string $expense, int $count)
+    public function yearInOutSummarized(string $income, string $expense, int $count): array
     {
 
         $data                          = [
diff --git a/app/Generator/Chart/Report/ReportChartGeneratorInterface.php b/app/Generator/Chart/Report/ReportChartGeneratorInterface.php
index c08654bd56..333bff112b 100644
--- a/app/Generator/Chart/Report/ReportChartGeneratorInterface.php
+++ b/app/Generator/Chart/Report/ReportChartGeneratorInterface.php
@@ -25,7 +25,7 @@ interface ReportChartGeneratorInterface
      *
      * @return array
      */
-    public function multiYearInOut(Collection $entries);
+    public function multiYearInOut(Collection $entries): array;
 
     /**
      * @param string $income
@@ -34,14 +34,14 @@ interface ReportChartGeneratorInterface
      *
      * @return array
      */
-    public function multiYearInOutSummarized(string $income, string $expense, int $count);
+    public function multiYearInOutSummarized(string $income, string $expense, int $count): array;
 
     /**
      * @param Collection $entries
      *
      * @return array
      */
-    public function yearInOut(Collection $entries);
+    public function yearInOut(Collection $entries): array;
 
     /**
      * @param string $income
@@ -50,6 +50,6 @@ interface ReportChartGeneratorInterface
      *
      * @return array
      */
-    public function yearInOutSummarized(string $income, string $expense, int $count);
+    public function yearInOutSummarized(string $income, string $expense, int $count): array;
 
 }
diff --git a/app/Handlers/Events/ConnectJournalToPiggyBank.php b/app/Handlers/Events/ConnectJournalToPiggyBank.php
index 83da596d09..3a7d0bbb49 100644
--- a/app/Handlers/Events/ConnectJournalToPiggyBank.php
+++ b/app/Handlers/Events/ConnectJournalToPiggyBank.php
@@ -17,25 +17,14 @@ use FireflyIII\Models\TransactionJournal;
 class ConnectJournalToPiggyBank
 {
 
-    /**
-     * Create the event handler.
-     *
-     * @codeCoverageIgnore
-     *
-     */
-    public function __construct()
-    {
-        //
-    }
-
     /**
      * Connect a new transaction journal to any related piggy banks.
      *
      * @param  TransactionJournalStored $event
      *
-     * @return boolean
+     * @return bool
      */
-    public function handle(TransactionJournalStored $event)
+    public function handle(TransactionJournalStored $event): bool
     {
         /** @var TransactionJournal $journal */
         $journal     = $event->journal;
diff --git a/app/Handlers/Events/FireRulesForStore.php b/app/Handlers/Events/FireRulesForStore.php
index 818f25ccdf..e7aeb8ddf1 100644
--- a/app/Handlers/Events/FireRulesForStore.php
+++ b/app/Handlers/Events/FireRulesForStore.php
@@ -26,25 +26,15 @@ use Log;
  */
 class FireRulesForStore
 {
-    /**
-     * Create the event handler.
-     *
-     * @codeCoverageIgnore
-     *
-     */
-    public function __construct()
-    {
-        //
-    }
 
     /**
      * Connect a new transaction journal to any related piggy banks.
      *
      * @param  TransactionJournalStored $event
      *
-     * @return boolean
+     * @return bool
      */
-    public function handle(TransactionJournalStored $event)
+    public function handle(TransactionJournalStored $event): bool
     {
         // get all the user's rule groups, with the rules, order by 'order'.
         /** @var User $user */
diff --git a/app/Handlers/Events/FireRulesForUpdate.php b/app/Handlers/Events/FireRulesForUpdate.php
index 32db77f3c0..fce152f3b9 100644
--- a/app/Handlers/Events/FireRulesForUpdate.php
+++ b/app/Handlers/Events/FireRulesForUpdate.php
@@ -25,23 +25,14 @@ use Log;
  */
 class FireRulesForUpdate
 {
-    /**
-     * Create the event handler.
-     *
-     */
-    public function __construct()
-    {
-        //
-    }
-
     /**
      * Handle the event.
      *
      * @param  TransactionJournalUpdated $event
      *
-     * @return void
+     * @return bool
      */
-    public function handle(TransactionJournalUpdated $event)
+    public function handle(TransactionJournalUpdated $event): bool
     {
         // get all the user's rule groups, with the rules, order by 'order'.
         /** @var User $user */
@@ -71,5 +62,6 @@ class FireRulesForUpdate
 
             }
         }
+        return true;
     }
 }
diff --git a/app/Handlers/Events/ScanForBillsAfterStore.php b/app/Handlers/Events/ScanForBillsAfterStore.php
index 39cedad621..3106634487 100644
--- a/app/Handlers/Events/ScanForBillsAfterStore.php
+++ b/app/Handlers/Events/ScanForBillsAfterStore.php
@@ -22,26 +22,18 @@ use FireflyIII\Support\Events\BillScanner;
 class ScanForBillsAfterStore
 {
 
-    /**
-     * Create the event handler.
-     *
-     */
-    public function __construct()
-    {
-        //
-    }
-
     /**
      * Scan a transaction journal for possible links to bills, right after storing.
      *
      * @param  TransactionJournalStored $event
      *
-     * @return void
+     * @return bool
      */
-    public function handle(TransactionJournalStored $event)
+    public function handle(TransactionJournalStored $event): bool
     {
         $journal = $event->journal;
         BillScanner::scan($journal);
+        return true;
     }
 
 }
diff --git a/app/Handlers/Events/ScanForBillsAfterUpdate.php b/app/Handlers/Events/ScanForBillsAfterUpdate.php
index 1b82f7956c..c2dee9ea12 100644
--- a/app/Handlers/Events/ScanForBillsAfterUpdate.php
+++ b/app/Handlers/Events/ScanForBillsAfterUpdate.php
@@ -21,27 +21,18 @@ use FireflyIII\Support\Events\BillScanner;
  */
 class ScanForBillsAfterUpdate
 {
-
-    /**
-     * Create the event handler.
-     *
-     */
-    public function __construct()
-    {
-        //
-    }
-
     /**
      * Scan a transaction journal for possibly related bills after it has been updated.
      *
      * @param  TransactionJournalUpdated $event
      *
-     * @return void
+     * @return bool
      */
-    public function handle(TransactionJournalUpdated $event)
+    public function handle(TransactionJournalUpdated $event): bool
     {
         $journal = $event->journal;
         BillScanner::scan($journal);
+        return true;
     }
 
 }
diff --git a/app/Handlers/Events/UpdateJournalConnection.php b/app/Handlers/Events/UpdateJournalConnection.php
index a42be4cf81..7328caa16a 100644
--- a/app/Handlers/Events/UpdateJournalConnection.php
+++ b/app/Handlers/Events/UpdateJournalConnection.php
@@ -15,23 +15,14 @@ use FireflyIII\Models\PiggyBankRepetition;
 class UpdateJournalConnection
 {
 
-    /**
-     * Create the event handler.
-     *
-     */
-    public function __construct()
-    {
-        //
-    }
-
     /**
      * Handle the event.
      *
      * @param  TransactionJournalUpdated $event
      *
-     * @return void
+     * @return bool
      */
-    public function handle(TransactionJournalUpdated $event)
+    public function handle(TransactionJournalUpdated $event):bool
     {
         $journal = $event->journal;
 
@@ -39,7 +30,7 @@ class UpdateJournalConnection
         /** @var PiggyBankEvent $event */
         $event = PiggyBankEvent::where('transaction_journal_id', $journal->id)->first();
         if (is_null($event)) {
-            return;
+            return false;
         }
         $piggyBank  = $event->piggyBank()->first();
         $repetition = null;
@@ -49,7 +40,7 @@ class UpdateJournalConnection
         }
 
         if (is_null($repetition)) {
-            return;
+            return false;
         }
         bcscale(2);
 
@@ -62,6 +53,8 @@ class UpdateJournalConnection
 
         $event->amount = $amount;
         $event->save();
+
+        return true;
     }
 
 }
diff --git a/app/Helpers/Attachments/AttachmentHelper.php b/app/Helpers/Attachments/AttachmentHelper.php
index d90e254ae2..08e9086af4 100644
--- a/app/Helpers/Attachments/AttachmentHelper.php
+++ b/app/Helpers/Attachments/AttachmentHelper.php
@@ -46,7 +46,7 @@ class AttachmentHelper implements AttachmentHelperInterface
      *
      * @return string
      */
-    public function getAttachmentLocation(Attachment $attachment)
+    public function getAttachmentLocation(Attachment $attachment): string
     {
         $path = storage_path('upload') . DIRECTORY_SEPARATOR . 'at-' . $attachment->id . '.data';
 
@@ -56,7 +56,7 @@ class AttachmentHelper implements AttachmentHelperInterface
     /**
      * @return MessageBag
      */
-    public function getErrors()
+    public function getErrors(): MessageBag
     {
         return $this->errors;
     }
@@ -64,7 +64,7 @@ class AttachmentHelper implements AttachmentHelperInterface
     /**
      * @return MessageBag
      */
-    public function getMessages()
+    public function getMessages(): MessageBag
     {
         return $this->messages;
     }
@@ -74,7 +74,7 @@ class AttachmentHelper implements AttachmentHelperInterface
      *
      * @return bool
      */
-    public function saveAttachmentsForModel(Model $model)
+    public function saveAttachmentsForModel(Model $model): bool
     {
         $files = null;
         try {
@@ -107,7 +107,7 @@ class AttachmentHelper implements AttachmentHelperInterface
      *
      * @return bool
      */
-    protected function hasFile(UploadedFile $file, Model $model)
+    protected function hasFile(UploadedFile $file, Model $model): bool
     {
         $md5   = md5_file($file->getRealPath());
         $name  = $file->getClientOriginalName();
@@ -125,16 +125,17 @@ class AttachmentHelper implements AttachmentHelperInterface
     }
 
     /**
+     *
      * @param UploadedFile $file
      * @param Model        $model
      *
-     * @return bool|Attachment
+     * @return Attachment
      */
-    protected function processFile(UploadedFile $file, Model $model)
+    protected function processFile(UploadedFile $file, Model $model): Attachment
     {
         $validation = $this->validateUpload($file, $model);
         if ($validation === false) {
-            return false;
+            return new Attachment;
         }
 
         $attachment = new Attachment; // create Attachment object.
@@ -175,7 +176,7 @@ class AttachmentHelper implements AttachmentHelperInterface
      *
      * @return bool
      */
-    protected function validMime(UploadedFile $file)
+    protected function validMime(UploadedFile $file): bool
     {
         $mime = e($file->getMimeType());
         $name = e($file->getClientOriginalName());
@@ -195,7 +196,7 @@ class AttachmentHelper implements AttachmentHelperInterface
      *
      * @return bool
      */
-    protected function validSize(UploadedFile $file)
+    protected function validSize(UploadedFile $file): bool
     {
         $size = $file->getSize();
         $name = e($file->getClientOriginalName());
@@ -215,7 +216,7 @@ class AttachmentHelper implements AttachmentHelperInterface
      *
      * @return bool
      */
-    protected function validateUpload(UploadedFile $file, Model $model)
+    protected function validateUpload(UploadedFile $file, Model $model): bool
     {
         if (!$this->validMime($file)) {
             return false;
diff --git a/app/Helpers/Attachments/AttachmentHelperInterface.php b/app/Helpers/Attachments/AttachmentHelperInterface.php
index 84f86624a8..51e7c84628 100644
--- a/app/Helpers/Attachments/AttachmentHelperInterface.php
+++ b/app/Helpers/Attachments/AttachmentHelperInterface.php
@@ -17,25 +17,25 @@ interface AttachmentHelperInterface
     /**
      * @param Attachment $attachment
      *
-     * @return mixed
+     * @return string
      */
-    public function getAttachmentLocation(Attachment $attachment);
+    public function getAttachmentLocation(Attachment $attachment): string;
 
     /**
      * @return MessageBag
      */
-    public function getErrors();
+    public function getErrors(): MessageBag;
 
     /**
      * @return MessageBag
      */
-    public function getMessages();
+    public function getMessages(): MessageBag;
 
     /**
      * @param Model $model
      *
      * @return bool
      */
-    public function saveAttachmentsForModel(Model $model);
+    public function saveAttachmentsForModel(Model $model): bool;
 
 }
diff --git a/app/Helpers/Collection/Account.php b/app/Helpers/Collection/Account.php
index a327f2760b..b9256a0a9a 100644
--- a/app/Helpers/Collection/Account.php
+++ b/app/Helpers/Collection/Account.php
@@ -23,9 +23,9 @@ class Account
     protected $start;
 
     /**
-     * @return \Illuminate\Support\Collection
+     * @return Collection
      */
-    public function getAccounts()
+    public function getAccounts(): Collection
     {
         return $this->accounts;
     }
@@ -41,7 +41,7 @@ class Account
     /**
      * @return string
      */
-    public function getDifference()
+    public function getDifference(): string
     {
         return $this->difference;
     }
@@ -57,7 +57,7 @@ class Account
     /**
      * @return string
      */
-    public function getEnd()
+    public function getEnd(): string
     {
         return $this->end;
     }
@@ -73,7 +73,7 @@ class Account
     /**
      * @return string
      */
-    public function getStart()
+    public function getStart(): string
     {
         return $this->start;
     }
diff --git a/app/Helpers/Collection/Balance.php b/app/Helpers/Collection/Balance.php
index b075ac3482..82549b9248 100644
--- a/app/Helpers/Collection/Balance.php
+++ b/app/Helpers/Collection/Balance.php
@@ -39,7 +39,7 @@ class Balance
     /**
      * @return BalanceHeader
      */
-    public function getBalanceHeader()
+    public function getBalanceHeader(): BalanceHeader
     {
         return $this->balanceHeader;
     }
@@ -53,9 +53,9 @@ class Balance
     }
 
     /**
-     * @return \Illuminate\Support\Collection
+     * @return Collection
      */
-    public function getBalanceLines()
+    public function getBalanceLines(): Collection
     {
         return $this->balanceLines;
     }