1 files changed, 1 insertions, 1 deletions
diff --git a/gr-blocks/lib/file_sink_impl.h b/gr-blocks/lib/file_sink_impl.h
index 3671aab540..4b6685ab0c 100644
--- a/gr-blocks/lib/file_sink_impl.h
+++ b/gr-blocks/lib/file_sink_impl.h
@@ -31,7 +31,7 @@ namespace blocks {
 class file_sink_impl : public file_sink
 {
 private:
-    size_t d_itemsize;
+    const size_t d_itemsize;
 
 public:
     file_sink_impl(size_t itemsize, const char* filename, bool append = false);