diff --git a/hash_writer.zig b/hash_writer.zig
index eb38ee9b7a09fd4b30428b0bc43da787991ddc77..a7865808487e6186a462d80a843821fd462a83df 100644
--- a/hash_writer.zig
+++ b/hash_writer.zig
@@ -3,6 +3,7 @@
 const std = @import("std");
 const nio = @import("./nio.zig");
 const builtin = @import("builtin");
+const extras = @import("extras");
 
 const sys = switch (builtin.target.os.tag) {
     .linux => @import("sys-linux"),
@@ -23,6 +24,10 @@ pub fn HashWriter(comptime Hash: type) type {
             };
         }
 
+        pub fn from(hasher: anytype) HashWriter(extras.Pointee(@TypeOf(hasher))) {
+            return .init(hasher);
+        }
+
         const W = nio.Writable(@This(), ._const);
         pub const writeAll = W.writeAll;
         pub const writevAll = W.writevAll;