diff --git a/Kernel/FileSystem/BlockBasedFileSystem.cpp b/Kernel/FileSystem/BlockBasedFileSystem.cpp
index 489f534439..6361c90178 100644
--- a/Kernel/FileSystem/BlockBasedFileSystem.cpp
+++ b/Kernel/FileSystem/BlockBasedFileSystem.cpp
@@ -131,7 +131,7 @@ ErrorOr<void> BlockBasedFileSystem::initialize()
     return {};
 }
 
-ErrorOr<void> BlockBasedFileSystem::write_block(BlockIndex index, const UserOrKernelBuffer& data, size_t count, size_t offset, bool allow_cache)
+ErrorOr<void> BlockBasedFileSystem::write_block(BlockIndex index, const UserOrKernelBuffer& data, size_t count, u64 offset, bool allow_cache)
 {
     VERIFY(m_logical_block_size);
     VERIFY(offset + count <= block_size());
@@ -147,7 +147,7 @@ ErrorOr<void> BlockBasedFileSystem::write_block(BlockIndex index, const UserOrKe
     return m_cache.with_exclusive([&](auto& cache) -> ErrorOr<void> {
         if (!allow_cache) {
             flush_specific_block_if_needed(index);
-            auto base_offset = index.value() * block_size() + offset;
+            u64 base_offset = index.value() * block_size() + offset;
             auto nwritten = TRY(file_description().write(base_offset, data, count));
             VERIFY(nwritten == count);
             return {};
diff --git a/Kernel/FileSystem/BlockBasedFileSystem.h b/Kernel/FileSystem/BlockBasedFileSystem.h
index f1cfa29818..2355aba79b 100644
--- a/Kernel/FileSystem/BlockBasedFileSystem.h
+++ b/Kernel/FileSystem/BlockBasedFileSystem.h
@@ -35,7 +35,7 @@ protected:
     ErrorOr<void> raw_read_blocks(BlockIndex index, size_t count, UserOrKernelBuffer&);
     ErrorOr<void> raw_write_blocks(BlockIndex index, size_t count, const UserOrKernelBuffer&);
 
-    ErrorOr<void> write_block(BlockIndex, const UserOrKernelBuffer&, size_t count, size_t offset = 0, bool allow_cache = true);
+    ErrorOr<void> write_block(BlockIndex, const UserOrKernelBuffer&, size_t count, u64 offset = 0, bool allow_cache = true);
     ErrorOr<void> write_blocks(BlockIndex, unsigned count, const UserOrKernelBuffer&, bool allow_cache = true);
 
     u64 m_logical_block_size { 512 };