diff --git a/compression/python/compression_clif_aux.cc b/compression/python/compression_clif_aux.cc
index 6c938d95..334530a8 100644
--- a/compression/python/compression_clif_aux.cc
+++ b/compression/python/compression_clif_aux.cc
@@ -72,7 +72,9 @@ class SbsWriterImpl : public WriterInterface {
   }
 
   void AddScales(const std::vector<float>& scales) override {
-    compressor_.AddScales(scales.data(), scales.size());
+    HWY_ASSERT(scales_.empty());
+    scales_ = scales;
+    compressor_.AddScales(scales_.data(), scales_.size());
   }
 
   void Write(std::string path) override {
@@ -85,6 +87,7 @@ class SbsWriterImpl : public WriterInterface {
   std::vector<std::vector<SfpStream>> sfp_streams_;
   std::vector<std::vector<NuqStream>> nuq_streams_;
   std::vector<std::vector<hwy::bfloat16_t>> bf16_streams_;
+  std::vector<float> scales_;
 };
 
 WriterInterface* NewSbsWriter() { return new SbsWriterImpl(); }