diff --git a/src/reader.rs b/src/reader.rs
index a7e9891..68f57a6 100644
--- a/src/reader.rs
+++ b/src/reader.rs
@@ -679,6 +679,16 @@ impl Archive {
             if !archive.files[i].has_stream {
                 continue;
             }
+
+            //set `compressed_size` of first file in block
+            if stream_map.folder_first_file_index[next_folder_index] == i {
+                let first_pack_stream_index =
+                    stream_map.folder_first_pack_stream_index[next_folder_index];
+                let pack_size = archive.pack_sizes[first_pack_stream_index];
+
+                archive.files[i].compressed_size = pack_size;
+            }
+
             next_folder_unpack_stream_index += 1;
             if next_folder_unpack_stream_index
                 >= archive.folders[next_folder_index].num_unpack_sub_streams
diff --git a/tests/decompression_tests.rs b/tests/decompression_tests.rs
index 9ba686e..acff5d6 100644
--- a/tests/decompression_tests.rs
+++ b/tests/decompression_tests.rs
@@ -153,3 +153,30 @@ fn test_bcj2() {
         .unwrap();
     }
 }
+
+#[test]
+fn test_entry_compressed_size() {
+    let dir = std::fs::read_dir("tests/resources").unwrap();
+    for entry in dir {
+        let path = entry.unwrap().path();
+        if path.to_string_lossy().ends_with("7z") {
+            println!("{:?}", path);
+            let mut file = File::open(path).unwrap();
+            let file_len = file.metadata().unwrap().len();
+            let archive = Archive::read(&mut file, file_len, &[]).unwrap();
+            for i in 0..archive.folders.len() {
+                let fi = archive.stream_map.folder_first_file_index[i];
+                let file = &archive.files[fi];
+                println!(
+                    "\t:{}\tsize={}, \tcompressed={}",
+                    file.name(),
+                    file.size,
+                    file.compressed_size
+                );
+                if file.has_stream && file.size > 0 {
+                    assert!(file.compressed_size > 0);
+                }
+            }
+        }
+    }
+}