diff --git a/src/mux/anim_encode.c b/src/mux/anim_encode.c
index c07ab7e5..9f46d3f3 100644
--- a/src/mux/anim_encode.c
+++ b/src/mux/anim_encode.c
@@ -768,9 +768,10 @@ typedef struct {
 // Generates a candidate encoded frame given a picture and metadata.
 static WebPEncodingError EncodeCandidate(WebPPicture* const sub_frame,
                                          const FrameRect* const rect,
-                                         const WebPConfig* const config,
+                                         const WebPConfig* const encoder_config,
                                          int use_blending,
                                          Candidate* const candidate) {
+  WebPConfig config = *encoder_config;
   WebPEncodingError error_code = VP8_ENC_OK;
   assert(candidate != NULL);
   memset(candidate, 0, sizeof(*candidate));
@@ -788,7 +789,13 @@ static WebPEncodingError EncodeCandidate(WebPPicture* const sub_frame,
   // Encode picture.
   WebPMemoryWriterInit(&candidate->mem_);
 
-  if (!EncodeFrame(config, sub_frame, &candidate->mem_)) {
+  if (!config.lossless && use_blending) {
+    // Disable filtering to avoid blockiness in reconstructed frames at the
+    // time of decoding.
+    config.autofilter = 0;
+    config.filter_strength = 0;
+  }
+  if (!EncodeFrame(&config, sub_frame, &candidate->mem_)) {
     error_code = sub_frame->error_code;
     goto Err;
   }