diff --git a/src/avalanche.h b/src/avalanche.h
--- a/src/avalanche.h
+++ b/src/avalanche.h
@@ -144,9 +144,14 @@
 class AvalancheBlockUpdate {
     union {
         CBlockIndex *pindex;
-        size_t raw;
+        uintptr_t raw;
     };
 
+    static const size_t BITS = 2;
+    static const uintptr_t MASK = (1 << BITS) - 1;
+
+    static_assert(alignof(CBlockIndex) >= 1 << BITS);
+
 public:
     enum Status : uint8_t {
         Invalid,
@@ -160,10 +165,10 @@
         raw |= statusIn;
     }
 
-    Status getStatus() const { return Status(raw & 0x03); }
+    Status getStatus() const { return Status(raw & MASK); }
 
     CBlockIndex *getBlockIndex() {
-        return reinterpret_cast<CBlockIndex *>(raw & -size_t(0x04));
+        return reinterpret_cast<CBlockIndex *>(raw & ~MASK);
     }
 
     const CBlockIndex *getBlockIndex() const {