diff --git a/system/src/Grav/Common/Page/Medium/ImageMedium.php b/system/src/Grav/Common/Page/Medium/ImageMedium.php
index 05bc4c486c..8be914e12c 100644
--- a/system/src/Grav/Common/Page/Medium/ImageMedium.php
+++ b/system/src/Grav/Common/Page/Medium/ImageMedium.php
@@ -301,6 +301,8 @@ public function derivatives($min_width, $max_width = 2500, $step = 200) {
                 $derivative->set('width', $width);
                 $derivative->set('height', $height);
 
+                $derivative->saveImage();
+                $derivative->resetImage();
                 $this->addAlternative($ratio, $derivative);
             }
         }
@@ -559,6 +561,14 @@ protected function image()
         return $this;
     }
 
+    /**
+     * Frees the cached image file.
+     */
+    protected function resetImage()
+    {
+        $this->image = null;
+    }
+
     /**
      * Save the image with cache.
      *
@@ -587,7 +597,9 @@ protected function saveImage()
             $this->image->merge(ImageFile::open($overlay));
         }
 
-        return $this->image->cacheFile($this->format, $this->quality);
+        $cachedPath = $this->image->cacheFile($this->format, $this->quality);
+        $this->set('filepath', $cachedPath);
+        return $cachedPath;
     }
 
     /**