diff --git a/libheif/codecs/uncompressed/unc_codec.cc b/libheif/codecs/uncompressed/unc_codec.cc
index bd3e54a9a7..0ce5759f32 100644
--- a/libheif/codecs/uncompressed/unc_codec.cc
+++ b/libheif/codecs/uncompressed/unc_codec.cc
@@ -237,14 +237,14 @@ Error UncompressedImageCodec::get_heif_chroma_uncompressed(const std::shared_ptr
                                                            const std::shared_ptr<const Box_cmpd>& cmpd,
                                                            heif_chroma* out_chroma, heif_colorspace* out_colourspace)
 {
+  *out_chroma = heif_chroma_undefined;
+  *out_colourspace = heif_colorspace_undefined;
+
   Error error = check_header_validity(std::nullopt, cmpd, uncC);
   if (error) {
     return error;
   }
 
-  *out_chroma = heif_chroma_undefined;
-  *out_colourspace = heif_colorspace_undefined;
-
   if (isKnownUncompressedFrameConfigurationBoxProfile(uncC)) {
     *out_chroma = heif_chroma_444;
     *out_colourspace = heif_colorspace_RGB;
@@ -438,8 +438,9 @@ Result<std::shared_ptr<HeifPixelImage>> UncompressedImageCodec::create_image(con
                                                                              uint32_t height)
 {
   auto img = std::make_shared<HeifPixelImage>();
-  heif_chroma chroma;
-  heif_colorspace colourspace;
+  heif_chroma chroma = heif_chroma_undefined;
+  heif_colorspace colourspace = heif_colorspace_undefined;
+
   Error error = get_heif_chroma_uncompressed(uncC, cmpd, &chroma, &colourspace);
   if (error) {
     return error;