diff --git a/lix/libutil/async-io.cc b/lix/libutil/async-io.cc
index 0255097f7..9ecc3ec93 100644
--- a/lix/libutil/async-io.cc
+++ b/lix/libutil/async-io.cc
@@ -71,13 +71,4 @@ try {
 } catch (...) {
     return {result::current_exception()};
 }
-
-kj::Promise<Result<size_t>> AsyncFdInputStream::read(void * buffer, size_t size)
-{
-    if (auto got = ::read(fd, buffer, size); got >= 0) {
-        return {result::success(size_t(got))};
-    } else {
-        return {result::failure(std::make_exception_ptr(SysError(errno, "read failed")))};
-    }
-}
 }
diff --git a/lix/libutil/async-io.hh b/lix/libutil/async-io.hh
index 237c28e04..a443bcd80 100644
--- a/lix/libutil/async-io.hh
+++ b/lix/libutil/async-io.hh
@@ -77,20 +77,4 @@ public:
 
     kj::Promise<Result<size_t>> read(void * data, size_t len) override;
 };
-
-class AsyncFdInputStream : public AsyncInputStream
-{
-    int fd;
-    AutoCloseFD ownedFd; // only for closing automatically, must equal fd if set
-
-public:
-    struct shared_fd
-    {};
-
-    explicit AsyncFdInputStream(AutoCloseFD fd) : fd(fd.get()), ownedFd(std::move(fd)) {}
-    AsyncFdInputStream(shared_fd, int fd) : fd(fd) {}
-
-    kj::Promise<Result<size_t>> read(void * buffer, size_t size) override;
-};
-
 }