diff --git a/fs_mgr/libsnapshot/include/libsnapshot/cow_format.h b/fs_mgr/libsnapshot/include/libsnapshot/cow_format.h
index 69079cb23..6baf4beae 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/cow_format.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/cow_format.h
@@ -28,9 +28,6 @@ static constexpr uint32_t kCowVersionMinor = 0;
 
 static constexpr uint32_t kCowVersionManifest = 2;
 
-static constexpr size_t BLOCK_SZ = 4096;
-static constexpr size_t BLOCK_SHIFT = (__builtin_ffs(BLOCK_SZ) - 1);
-
 // This header appears as the first sequence of bytes in the COW. All fields
 // in the layout are little-endian encoded. The on-disk layout is:
 //
diff --git a/fs_mgr/libsnapshot/libsnapshot_cow/cow_format.cpp b/fs_mgr/libsnapshot/libsnapshot_cow/cow_format.cpp
index 94c41093c..2157d0fa9 100644
--- a/fs_mgr/libsnapshot/libsnapshot_cow/cow_format.cpp
+++ b/fs_mgr/libsnapshot/libsnapshot_cow/cow_format.cpp
@@ -57,8 +57,6 @@ std::ostream& operator<<(std::ostream& os, CowOperation const& op) {
     os << "data_length:" << op.data_length << ",\t";
     os << "new_block:" << op.new_block << ",\t";
     os << "source:" << op.source;
-    if (op.type == kCowXorOp)
-        os << " (block:" << op.source / BLOCK_SZ << " offset:" << op.source % BLOCK_SZ << ")";
     os << ")";
     return os;
 }
diff --git a/fs_mgr/libsnapshot/libsnapshot_cow/cow_reader.cpp b/fs_mgr/libsnapshot/libsnapshot_cow/cow_reader.cpp
index 893d95fc7..bc6528517 100644
--- a/fs_mgr/libsnapshot/libsnapshot_cow/cow_reader.cpp
+++ b/fs_mgr/libsnapshot/libsnapshot_cow/cow_reader.cpp
@@ -517,8 +517,8 @@ bool CowReader::VerifyMergeOps() {
             block = op.source;
             offset = false;
         } else if (op.type == kCowXorOp) {
-            block = op.source / BLOCK_SZ;
-            offset = (op.source % BLOCK_SZ) != 0;
+            block = op.source / header_.block_size;
+            offset = (op.source % header_.block_size) != 0;
         } else {
             itr->Next();
             continue;
diff --git a/fs_mgr/libsnapshot/snapuserd/include/snapuserd/snapuserd_kernel.h b/fs_mgr/libsnapshot/snapuserd/include/snapuserd/snapuserd_kernel.h
index c592257ca..46952c4ed 100644
--- a/fs_mgr/libsnapshot/snapuserd/include/snapuserd/snapuserd_kernel.h
+++ b/fs_mgr/libsnapshot/snapuserd/include/snapuserd/snapuserd_kernel.h
@@ -41,6 +41,9 @@ static constexpr uint32_t SNAPSHOT_VALID = 1;
  */
 static constexpr uint32_t SECTOR_SHIFT = 9;
 
+static constexpr size_t BLOCK_SZ = 4096;
+static constexpr size_t BLOCK_SHIFT = (__builtin_ffs(BLOCK_SZ) - 1);
+
 typedef __u64 sector_t;
 typedef sector_t chunk_t;