--- a/QuadFloat.st	Tue Jun 11 00:01:17 2019 +0200
+++ b/QuadFloat.st	Tue Jun 11 00:02:04 2019 +0200
@@ -2164,7 +2164,7 @@
     uiA64 = uA.ui.v64;
     uiA0  = uA.ui.v0;
     if (isNaNF128UI( uiA64, uiA0 )) return a;
-    uA.ui.v64 ^= 0x8000000000000000;
+    uA.ui.v64 ^= UINT64_C(0x8000000000000000);
     return uA.f;
 }