diff --git a/src/views/draganddrophelper.cpp b/src/views/draganddrophelper.cpp
--- a/src/views/draganddrophelper.cpp
+++ b/src/views/draganddrophelper.cpp
@@ -29,12 +29,25 @@
 #include <KIO/DropJob>
 #include <KJobWidgets>
 
-
 bool DragAndDropHelper::urlListMatchesUrl(const QList<QUrl>& urls, const QUrl& destUrl)
 {
-    return std::find_if(urls.constBegin(), urls.constEnd(), [destUrl](const QUrl& url) {
+    // This method is quite expensive and can be called several times. Use a cache.
+    static bool lastResult = false;
+    static const QList<QUrl>* lastUrls = nullptr;
+    static const QUrl* lastDestUrl = nullptr;
+
+    // If checking the same data as last time, return the same resutl.
+    if (&urls == lastUrls && &destUrl == lastDestUrl) {
+        return lastResult;
+    }
+    // otherwise do the expensive check and store the results
+    lastResult = std::find_if(urls.constBegin(), urls.constEnd(), [destUrl](const QUrl& url) {
         return url.matches(destUrl, QUrl::StripTrailingSlash);
     }) != urls.constEnd();
+    lastUrls = &urls;
+    lastDestUrl = &destUrl;
+
+    return lastResult;
 }
 
 KIO::DropJob* DragAndDropHelper::dropUrls(const QUrl& destUrl, QDropEvent* event, QWidget* window)