diff --git a/bmc/main.cpp b/bmc/main.cpp
index 031871f..eeca589 100644
--- a/bmc/main.cpp
+++ b/bmc/main.cpp
@@ -60,26 +60,15 @@
     return HandlerPack(name, std::make_unique<FileHandler>(path));
 }
 
-/**
- * Returns the corresponding memory region size given the compiled
- * configuration.
- *
- * @return the size.
- */
-std::size_t GetMemoryRegionSize()
-{
 #ifdef NUVOTON_P2A_MBOX
-    constexpr std::size_t memoryRegionSize = 16 * 1024UL;
+static constexpr std::size_t memoryRegionSize = 16 * 1024UL;
 #elif defined NUVOTON_P2A_VGA
-    constexpr std::size_t memoryRegionSize = 4 * 1024 * 1024UL;
+static constexpr std::size_t memoryRegionSize = 4 * 1024 * 1024UL;
 #else
-    /* The maximum external buffer size we expect is 64KB. */
-    constexpr std::size_t memoryRegionSize = 64 * 1024UL;
+/* The maximum external buffer size we expect is 64KB. */
+static constexpr std::size_t memoryRegionSize = 64 * 1024UL;
 #endif
 
-    return memoryRegionSize;
-}
-
 } // namespace
 } // namespace ipmi_flash
 
@@ -99,8 +88,7 @@
 #ifdef ENABLE_PCI_BRIDGE
     supportedTransports.emplace_back(
         FirmwareFlags::UpdateFlags::p2a,
-        std::make_unique<PciDataHandler>(MAPPED_ADDRESS,
-                                         GetMemoryRegionSize()));
+        std::make_unique<PciDataHandler>(MAPPED_ADDRESS, memoryRegionSize));
 #endif
 
 #ifdef ENABLE_LPC_BRIDGE
@@ -108,12 +96,12 @@
     supportedTransports.emplace_back(
         FirmwareFlags::UpdateFlags::lpc,
         std::make_unique<LpcDataHandler>(LpcMapperAspeed::createAspeedMapper(
-            MAPPED_ADDRESS, GetMemoryRegionSize())));
+            MAPPED_ADDRESS, memoryRegionSize)));
 #elif defined(NUVOTON_LPC)
     supportedTransports.emplace_back(
         FirmwareFlags::UpdateFlags::lpc,
         std::make_unique<LpcDataHandler>(LpcMapperNuvoton::createNuvotonMapper(
-            MAPPED_ADDRESS, GetMemoryRegionSize())));
+            MAPPED_ADDRESS, memoryRegionSize)));
 #else
 #error "You must specify a hardware implementation."
 #endif