diff --git a/main.cpp b/main.cpp
index 29587ec..f8700b1 100644
--- a/main.cpp
+++ b/main.cpp
@@ -39,7 +39,7 @@
 FileHandler ubitarballHandler(TARBALL_STAGED_NAME);
 
 /* The maximum external buffer size we expect is 64KB. */
-static constexpr size_t memoryRegionSize = 64 * 1024UL;
+static constexpr std::size_t memoryRegionSize = 64 * 1024UL;
 
 #ifdef ENABLE_LPC_BRIDGE
 #if defined(ASPEED_LPC)