diff --git a/writer/HDF5Objects.cpp b/writer/HDF5Objects.cpp
index dd7e2393e..3b0f8beae 100644
--- a/writer/HDF5Objects.cpp
+++ b/writer/HDF5Objects.cpp
@@ -1009,7 +1009,7 @@ CompressionAlgorithm HDF5Dcpl::GetCompression() {
         return CompressionAlgorithm::NO_COMPRESSION;
 
     uint32_t cd_values[8];
-    size_t cd_nelemts = sizeof(cd_values);
+    size_t cd_nelemts = std::size(cd_values);
     memset(cd_values, 0, sizeof(cd_values));
 
     const auto filter = H5Pget_filter2(id, 0, nullptr, &cd_nelemts, cd_values, 0, nullptr, nullptr);
@@ -1031,7 +1031,7 @@ CompressionAlgorithm HDF5Dcpl::GetCompression() {
         return CompressionAlgorithm::BSHUF_LZ4;
     if (cd_values[4] == BSHUF_H5_COMPRESS_ZSTD)
         return CompressionAlgorithm::BSHUF_ZSTD;
-    throw JFJochException(JFJochExceptionCategory::HDF5,"Weird value of parameter " + std::to_string(cd_values[1]));
+    throw JFJochException(JFJochExceptionCategory::HDF5,"Weird value of parameter " + std::to_string(cd_values[4]));
 }
 
 std::string ExtractFilename(const std::string& str) {