diff --git a/autotests/jobtest.h b/autotests/jobtest.h
--- a/autotests/jobtest.h
+++ b/autotests/jobtest.h
@@ -97,6 +97,8 @@
     void moveDestAlreadyExistsAutoRename_data();
     void moveDestAlreadyExistsAutoRename();
 
+    void copyDirectoryAlreadyExistsSkip();
+
     void safeOverwrite();
     void safeOverwrite_data();
     void moveAndOverwrite();
diff --git a/autotests/jobtest.cpp b/autotests/jobtest.cpp
--- a/autotests/jobtest.cpp
+++ b/autotests/jobtest.cpp
@@ -1732,6 +1732,37 @@
     }
 }
 
+void JobTest::copyDirectoryAlreadyExistsSkip()
+{
+    // when copying a directory (which contains at least one file) to some location, and then
+    // copying the same dir to the same location again, and clicking "Skip" there should be no
+    // segmentation fault, bug 408350
+
+    const QString src = homeTmpDir() + "a";
+    createTestDirectory(src);
+    const QString dest = homeTmpDir() + "dest";
+    createTestDirectory(dest);
+
+    QUrl u = QUrl::fromLocalFile(src);
+    QUrl d = QUrl::fromLocalFile(dest);
+
+    KIO::Job *job = KIO::copy(u, d, KIO::HideProgressInfo);
+    job->setUiDelegate(nullptr);
+    QVERIFY(job->exec());
+    QVERIFY(QFile::exists(dest + QStringLiteral("/a/testfile")));
+
+    job = KIO::copy(u, d, KIO::HideProgressInfo);
+    // Simulate the user pressing "Skip" in the dialog.
+    PredefinedAnswerJobUiDelegate extension;
+    extension.m_skipResult = KIO::S_SKIP;
+    job->setUiDelegateExtension(&extension);
+    QVERIFY(job->exec());
+    QVERIFY(QFile::exists(dest + QStringLiteral("/a/testfile")));
+
+    QDir(src).removeRecursively();
+    QDir(dest).removeRecursively();
+}
+
 void JobTest::safeOverwrite_data()
 {
     QTest::addColumn<bool>("destFileExists");
diff --git a/src/core/copyjob.cpp b/src/core/copyjob.cpp
--- a/src/core/copyjob.cpp
+++ b/src/core/copyjob.cpp
@@ -1637,7 +1637,7 @@
             it = files.erase(it);
         }
 
-        if ((*it).size > ((1ul << 32) - 1)) { // ((1ul << 32) - 1) = 4 GB
+        if (it != files.end() && (*it).size > ((1ul << 32) - 1)) { // ((1ul << 32) - 1) = 4 GB
             const auto fileSystem = KFileSystemType::fileSystemType(m_globalDest.toLocalFile());
             if (fileSystem == KFileSystemType::Fat) {
                 q->setError(ERR_FILE_TOO_LARGE_FOR_FAT32);