diff --git a/libde265/decctx.cc b/libde265/decctx.cc
index d046e0c6..6e96c402 100644
--- a/libde265/decctx.cc
+++ b/libde265/decctx.cc
@@ -2088,7 +2088,9 @@ bool decoder_context::process_slice_segment_header(slice_segment_header* hdr,
       img->PicState = UsedForShortTermReference;
 
       *err = process_reference_picture_set(hdr);
-      return false;
+      if (*err != DE265_OK) {
+        return false;
+      }
     }
 
     img->PicState = UsedForShortTermReference;
diff --git a/libde265/dpb.cc b/libde265/dpb.cc
index af448e32..77581a65 100644
--- a/libde265/dpb.cc
+++ b/libde265/dpb.cc
@@ -237,7 +237,7 @@ int decoded_picture_buffer::new_image(std::shared_ptr<const seq_parameter_set> s
 
   // create a new image slot if no empty slot remaining
 
-  if (free_image_buffer_idx == -1) {
+  if (free_image_buffer_idx == -DE265_ERROR_IMAGE_BUFFER_FULL) {
     free_image_buffer_idx = dpb.size();
     dpb.push_back(new de265_image);
   }