diff --git a/internal/sys.cpp b/internal/sys.cpp
index b99a2f2..46c6642 100644
--- a/internal/sys.cpp
+++ b/internal/sys.cpp
@@ -29,6 +29,11 @@
     return ::open(pathname, flags);
 }
 
+int SysImpl::read(int fd, void* buf, std::size_t count) const
+{
+    return static_cast<int>(::read(fd, buf, count));
+}
+
 int SysImpl::close(int fd) const
 {
     return ::close(fd);