diff --git a/cef1/libcef_dll/wrapper/cef_byte_read_handler.cc b/cef1/libcef_dll/wrapper/cef_byte_read_handler.cc
index 8ae5b2d8b..2d0b2085a 100644
--- a/cef1/libcef_dll/wrapper/cef_byte_read_handler.cc
+++ b/cef1/libcef_dll/wrapper/cef_byte_read_handler.cc
@@ -13,7 +13,7 @@ CefByteReadHandler::CefByteReadHandler(const unsigned char* bytes, size_t size,
 
 size_t CefByteReadHandler::Read(void* ptr, size_t size, size_t n) {
   AutoLock lock_scope(this);
-  size_t s = (size_ - offset_) / size;
+  size_t s = static_cast<size_t>(size_ - offset_) / size;
   size_t ret = std::min(n, s);
   memcpy(ptr, bytes_ + offset_, ret * size);
   offset_ += ret * size;