diff --git a/Classes/Hook/DataHandler.php b/Classes/Hook/DataHandler.php
index e0b8e40..6c3da5c 100644
--- a/Classes/Hook/DataHandler.php
+++ b/Classes/Hook/DataHandler.php
@@ -72,7 +72,7 @@ class DataHandler implements Singleton
     /**
      * Called by CoreDataHandler on deletion of records.
      */
-    public function processCmdmap_deleteAction(string $table, int $uid) : bool
+    public function processCmdmap_deleteAction(string $table, string $uid) : bool
     {
         if (! $this->shouldProcessHookForTable($table)) {
             $this->logger->debug('Delete not processed.', [$table, $uid]);
@@ -95,6 +95,10 @@ class DataHandler implements Singleton
                 $uid = $dataHandler->substNEWwithIDs[$uid];
             }
 
+            if (!is_numeric($uid) || $uid <= 0) {
+                continue;
+            }
+
             $this->processRecord($table, $uid);
         }
     }
diff --git a/Tests/Unit/Hook/DataHandlerTest.php b/Tests/Unit/Hook/DataHandlerTest.php
index ed68993..aaf3935 100644
--- a/Tests/Unit/Hook/DataHandlerTest.php
+++ b/Tests/Unit/Hook/DataHandlerTest.php
@@ -91,4 +91,46 @@ class DataHandlerToProcessorTest extends AbstractUnitTestCase
             ],
         ];
     }
+
+    /**
+     * @test
+     */
+    public function indexingIsNotCalledForCacheClearIfDataIsInvalid()
+    {
+        $coreDataHandlerMock = $this->getMockBuilder(CoreDataHandler::class)->getMock();
+        $ownDataHandlerMock = $this->getMockBuilder(OwnDataHandler::class)
+            ->disableOriginalConstructor()
+            ->getMock();
+
+        $subject = new DataHandler($ownDataHandlerMock);
+
+        $ownDataHandlerMock->expects($this->never())->method('update');
+
+        $subject->clearCachePostProc([
+            'cacheCmd' => 'NEW343',
+        ], $coreDataHandlerMock);
+    }
+    /**
+     * @test
+     */
+    public function indexingIsNotCalledForProcessIfDataIsInvalid()
+    {
+        $coreDataHandlerMock = $this->getMockBuilder(CoreDataHandler::class)->getMock();
+        $coreDataHandlerMock->datamap = [
+            'tt_content' => [
+                'NEW343' => [],
+            ],
+        ];
+        $coreDataHandlerMock->substNEWwithIDs = [];
+
+        $ownDataHandlerMock = $this->getMockBuilder(OwnDataHandler::class)
+            ->disableOriginalConstructor()
+            ->getMock();
+
+        $subject = new DataHandler($ownDataHandlerMock);
+
+        $ownDataHandlerMock->expects($this->never())->method('update');
+
+        $subject->processDatamap_afterAllOperations($coreDataHandlerMock);
+    }
 }