diff --git a/Tiano/EfiTianoDecompress.c b/Tiano/EfiTianoDecompress.c
index 7300bb5..10449f1 100644
--- a/Tiano/EfiTianoDecompress.c
+++ b/Tiano/EfiTianoDecompress.c
@@ -100,10 +100,10 @@ Returns: (VOID)
 
 --*/
 {
-	Sd->mBitBuf = (UINT32)(Sd->mBitBuf << NumOfBits);
+	Sd->mBitBuf = (UINT32) (((UINT64)Sd->mBitBuf) << NumOfBits);
 
 	while (NumOfBits > Sd->mBitCount) {
-		Sd->mBitBuf |= (UINT32)(Sd->mSubBitBuf << (NumOfBits = (UINT16)(NumOfBits - Sd->mBitCount)));
+		Sd->mBitBuf |= (UINT32) (((UINT64)Sd->mSubBitBuf) << (NumOfBits = (UINT16) (NumOfBits - Sd->mBitCount)));
 
 		if (Sd->mCompSize > 0) {
 			//