diff --git a/lib/net/bip152.js b/lib/net/bip152.js
index 28e42f28..1a33af0d 100644
--- a/lib/net/bip152.js
+++ b/lib/net/bip152.js
@@ -132,8 +132,11 @@ CompactBlock.prototype.fromRaw = function fromRaw(data) {
 
   this.totalTX += idCount;
 
-  for (let i = 0; i < idCount; i++)
-    this.ids.push(br.readU32() + br.readU16() * 0x100000000);
+  for (let i = 0; i < idCount; i++) {
+    const lo = br.readU32();
+    const hi = br.readU16();
+    this.ids.push(hi * 0x100000000 + lo);
+  }
 
   const txCount = br.readVarint();
 
@@ -259,8 +262,8 @@ CompactBlock.prototype.writeRaw = function writeRaw(bw, witness) {
 
   for (const id of this.ids) {
     const lo = id % 0x100000000;
-    let hi = (id - lo) / 0x100000000;
-    hi &= 0xffff;
+    const hi = (id - lo) / 0x100000000;
+    assert(hi <= 0xffff);
     bw.writeU32(lo);
     bw.writeU16(hi);
   }