--- a/libziparchive/zip_writer.cc
+++ b/libziparchive/zip_writer.cc
@@ -389,7 +389,7 @@
   CHECK(z_stream_->avail_out != 0);
 
   // Prepare the input.
-  z_stream_->next_in = reinterpret_cast<const uint8_t*>(data);
+  z_stream_->next_in = const_cast<uint8_t*>(reinterpret_cast<const uint8_t*>(data));
   z_stream_->avail_in = len;
 
   while (z_stream_->avail_in > 0) {