diff --git a/thumbnail/thumbnail.cpp b/thumbnail/thumbnail.cpp
--- a/thumbnail/thumbnail.cpp
+++ b/thumbnail/thumbnail.cpp
@@ -77,6 +77,7 @@
 #endif
 
 #include "imagefilter.h"
+#include <KMountPoint>
 
 // Recognized metadata entries:
 // mimeType     - the mime type of the file, used for the overlay icon if any
@@ -721,7 +722,13 @@
         }
         if (!thumbnail.load(thumbPath.absoluteFilePath(thumbName))) {
             // no cached version is available, a new thumbnail must be created
-
+            
+            const auto mountsList = KMountPoint::currentMountPoints();
+            const auto mount =  mountsList.findByPath(filePath);
+            const auto thumbRootMount = mountsList.findByPath(m_thumbBasePath);
+            //If file is on the same filesystem as thumbnail directory, we can cache it.
+            const bool isEncrypted = mount != thumbRootMount && (mount->mountType() == QLatin1String("fuse.cryfs") || mount->mountType() == QLatin1String("fuse.encfs"));
+            
             QSaveFile thumbnailfile(thumbPath.absoluteFilePath(thumbName));
             bool savedCorrectly = false;
             if (subCreator->create(filePath, cacheSize, cacheSize, thumbnail)) {
@@ -729,7 +736,7 @@
 
                 // The thumbnail has been created successfully. Store the thumbnail
                 // to the cache for future access.
-                if (thumbnailfile.open(QIODevice::WriteOnly | QIODevice::Truncate)) {
+                if (!isEncrypted && thumbnailfile.open(QIODevice::WriteOnly | QIODevice::Truncate)) {
                     savedCorrectly = thumbnail.save(&thumbnailfile, "PNG");
                 }
             } else {