diff --git a/OvmfPkg/Library/PlatformInitLib/MemDetect.c b/OvmfPkg/Library/PlatformInitLib/MemDetect.c
index f85a63ac51..aced8535e6 100644
--- a/OvmfPkg/Library/PlatformInitLib/MemDetect.c
+++ b/OvmfPkg/Library/PlatformInitLib/MemDetect.c
@@ -595,10 +595,12 @@ PlatformAddressWidthFromCpuid (
 {
   UINT32   RegEax, RegEbx, RegEcx, RegEdx, Max;
   UINT8    PhysBits;
-  CHAR8    Signature[13] = { 0 };
+  CHAR8    Signature[13];
   BOOLEAN  Valid         = FALSE;
   BOOLEAN  Page1GSupport = FALSE;
 
+  ZeroMem (Signature, sizeof (Signature));
+
   AsmCpuid (0x80000000, &RegEax, &RegEbx, &RegEcx, &RegEdx);
   *(UINT32 *)(Signature + 0) = RegEbx;
   *(UINT32 *)(Signature + 4) = RegEdx;