diff --git a/table/format.cc b/table/format.cc
index 3bc964424..c84a59904 100644
--- a/table/format.cc
+++ b/table/format.cc
@@ -463,7 +463,7 @@ Status UncompressBlockContents(const UncompressionInfo& uncompression_info,
                                const ImmutableCFOptions& ioptions,
                                MemoryAllocator* allocator) {
   assert(data[n] != kNoCompression);
-  assert(data[n] == uncompression_info.type());
+  assert(data[n] == static_cast<char>(uncompression_info.type()));
   return UncompressBlockContentsForCompressionType(uncompression_info, data, n,
                                                    contents, format_version,
                                                    ioptions, allocator);