diff --git a/source/blender/blenkernel/intern/seqprefetch.c b/source/blender/blenkernel/intern/seqprefetch.c
index d400f712728..dd074c643ac 100644
--- a/source/blender/blenkernel/intern/seqprefetch.c
+++ b/source/blender/blenkernel/intern/seqprefetch.c
@@ -536,11 +536,11 @@ void BKE_sequencer_prefetch_start(const SeqRenderData *context, float cfra, floa
     /* conditions to start:
      * prefetch enabled, prefetch not running, not scrubbing,
      * not playing and rendering-expensive footage, cache storage enabled, has strips to render,
-     * not rendering.
+     * not rendering, not doing modal transform - important, see D7820.
      */
     if ((ed->cache_flag & SEQ_CACHE_PREFETCH_ENABLE) && !running && !scrubbing &&
         !(playing && cost > 0.9) && ed->cache_flag & SEQ_CACHE_ALL_TYPES && has_strips &&
-        !G.is_rendering) {
+        !G.is_rendering && !G.moving) {
 
       seq_prefetch_start(context, cfra);
     }