diff --git a/filesystem/filesystem.cpp b/filesystem/filesystem.cpp
index 6100d1059..b740e23ed 100644
--- a/filesystem/filesystem.cpp
+++ b/filesystem/filesystem.cpp
@@ -391,8 +391,8 @@ FileHandle ScratchFilesystem::open(const std::string &path, FileMode)
 	}
 }
 
-BlobFilesystem::BlobFilesystem(FileHandle file_, std::string basedir_)
-	: file(std::move(file_)), base(std::move(basedir_))
+BlobFilesystem::BlobFilesystem(FileHandle file_)
+	: file(std::move(file_))
 {
 	if (!file)
 		return;
@@ -560,7 +560,7 @@ std::vector<ListEntry> BlobFilesystem::list(const std::string &path)
 	auto canon_path = Path::canonicalize_path(path);
 
 	std::vector<ListEntry> entries;
-	if (const auto *zip_dir = find_directory(Path::join(base, canon_path)))
+	if (const auto *zip_dir = find_directory(canon_path))
 	{
 		entries.reserve(zip_dir->dirs.size() + zip_dir->files.size());
 		for (auto &dir : zip_dir->dirs)
@@ -573,7 +573,7 @@ std::vector<ListEntry> BlobFilesystem::list(const std::string &path)
 
 bool BlobFilesystem::stat(const std::string &path, FileStat &stat)
 {
-	auto p = Path::join(base, Path::canonicalize_path(path));
+	auto p = Path::canonicalize_path(path);
 
 	if (const auto *zip_file = find_file(p))
 	{
@@ -598,7 +598,7 @@ FileHandle BlobFilesystem::open(const std::string &path, FileMode mode)
 	if (mode != FileMode::ReadOnly)
 		return {};
 
-	auto p = Path::join(base, Path::canonicalize_path(path));
+	auto p = Path::canonicalize_path(path);
 	auto *blob_file = find_file(p);
 	if (!blob_file)
 		return {};
diff --git a/filesystem/filesystem.hpp b/filesystem/filesystem.hpp
index 244fb5dc1..5ba1014d8 100644
--- a/filesystem/filesystem.hpp
+++ b/filesystem/filesystem.hpp
@@ -285,7 +285,7 @@ class FileSlice final : public File
 class BlobFilesystem final : public FilesystemBackend
 {
 public:
-	BlobFilesystem(FileHandle file, std::string basedir);
+	BlobFilesystem(FileHandle file);
 
 	std::vector<ListEntry> list(const std::string &path) override;
 
@@ -304,7 +304,6 @@ class BlobFilesystem final : public FilesystemBackend
 private:
 	FileHandle file;
 	size_t blob_base_offset = 0;
-	std::string base;
 
 	struct BlobFile
 	{