diff --git a/CHANGELOG.md b/CHANGELOG.md
index 90a1d8b7..8b39d4b2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,7 @@
 Version 267:
 
 * Add package for Travis config
+* Fix signed/unsigned mismatch in file_stdio::seek
 
 --------------------------------------------------------------------------------
 
diff --git a/include/boost/beast/core/impl/file_stdio.ipp b/include/boost/beast/core/impl/file_stdio.ipp
index 30adae62..e2d03a72 100644
--- a/include/boost/beast/core/impl/file_stdio.ipp
+++ b/include/boost/beast/core/impl/file_stdio.ipp
@@ -241,7 +241,7 @@ seek(std::uint64_t offset, error_code& ec)
         ec = make_error_code(errc::bad_file_descriptor);
         return;
     }
-    if(offset > (std::numeric_limits<long>::max)())
+    if(offset > static_cast<std::uint64_t>(std::numeric_limits<long>::max()))
     {
         ec = make_error_code(errc::invalid_seek);
         return;