diff --git a/MANIFEST.in b/MANIFEST.in
index feae2cb..968f3a6 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -20,3 +20,7 @@ graft third_party/re2
 
 # absl
 graft third_party/abseil-cpp
+
+# stb
+include third_party/stb/stb_image.h
+include third_party/stb/stb_image_resize2.h
diff --git a/chatglm.h b/chatglm.h
index 6f0d5e3..bc91024 100644
--- a/chatglm.h
+++ b/chatglm.h
@@ -354,8 +354,6 @@ struct Image {
 
     Image resize(size_t new_width, size_t new_height) const;
 
-    bool empty() const { return pixels.empty(); }
-
     void clear() {
         width = height = channels = 0;
         pixels.clear();