diff --git a/src/spider/runtime/instr/Instr_000-01F.cpp b/src/spider/runtime/instr/Instr_000-01F.cpp
index aaec58f..68bf4ce 100644
--- a/src/spider/runtime/instr/Instr_000-01F.cpp
+++ b/src/spider/runtime/instr/Instr_000-01F.cpp
@@ -373,16 +373,16 @@ namespace spider {
         fetchOperDst();
         switch(_size){
             case 0b00: //byte
-                RF = (RF & ~(0x3 << 9)) | ((_dst->_u8 >> 9) & 0x3) << 9;
+                RF = (RF & ~(u64(0x3) << 9)) | ((_dst->_u8 >> 9) & 0x3) << 9;
                 break;
             case 0b01: //short
-                RF = (RF & ~(0x3 << 9)) | ((_dst->_u16 >> 9) & 0x3) << 9;
+                RF = (RF & ~(u64(0x3) << 9)) | ((_dst->_u16 >> 9) & 0x3) << 9;
                 break;
             case 0b10: //int
-                RF = (RF & ~(0x3 << 9)) | ((_dst->_u32 >> 9) & 0x3) << 9;
+                RF = (RF & ~(u64(0x3) << 9)) | ((_dst->_u32 >> 9) & 0x3) << 9;
                 break;
             case 0b11: //long
-                RF = (RF & ~(0x3 << 9)) | ((_dst->_u64 >> 9) & 0x3) << 9;
+                RF = (RF & ~(u64(0x3) << 9)) | ((_dst->_u64 >> 9) & 0x3) << 9;
                 break;
         }
     }