Index: /trunk/src/VBox/Devices/Graphics/DevVGA_VBVA.cpp
===================================================================
--- /trunk/src/VBox/Devices/Graphics/DevVGA_VBVA.cpp	(revision 22728)
+++ /trunk/src/VBox/Devices/Graphics/DevVGA_VBVA.cpp	(revision 22729)
@@ -591,5 +591,5 @@
     }
 
-    return ~0;
+    return ~0U;
 }
 
@@ -1252,5 +1252,5 @@
             unsigned uScreenId = vbvaViewFromOffset (pIns, pCtx, pvBuffer);
 
-            if (uScreenId == ~0)
+            if (uScreenId == ~0U)
             {
                 rc = VERR_INVALID_PARAMETER;