diff --git a/lib/std/Progress.zig b/lib/std/Progress.zig
index 963e1b2869..cc94b1920e 100644
--- a/lib/std/Progress.zig
+++ b/lib/std/Progress.zig
@@ -608,12 +608,10 @@ pub fn unlockStdErr() void {
 }
 
 /// Protected by `stderr_mutex`.
-var stderr_buffered_writer: Writer = .{
-    .unbuffered_writer = stderr_file_writer.interface(),
-    .buffer = &.{},
-};
+const stderr_writer: *Writer = &stderr_file_writer.interface;
 /// Protected by `stderr_mutex`.
 var stderr_file_writer: std.fs.File.Writer = .{
+    .interface = std.fs.File.Writer.init_interface(&.{}),
     .file = if (is_windows) undefined else .stderr(),
     .mode = .streaming,
 };
@@ -628,14 +626,14 @@ pub fn lockStderrWriter(buffer: []u8) *Writer {
     stderr_mutex.lock();
     clearWrittenWithEscapeCodes() catch {};
     if (is_windows) stderr_file_writer.file = .stderr();
-    stderr_buffered_writer.flush() catch {};
-    stderr_buffered_writer.buffer = buffer;
-    return &stderr_buffered_writer;
+    stderr_writer.flush() catch {};
+    stderr_writer.buffer = buffer;
+    return &stderr_writer;
 }
 
 pub fn unlockStderrWriter() void {
-    stderr_buffered_writer.flush() catch {};
-    stderr_buffered_writer.buffer = &.{};
+    stderr_writer.flush() catch {};
+    stderr_writer.buffer = &.{};
     stderr_mutex.unlock();
 }
 
diff --git a/lib/std/crypto/phc_encoding.zig b/lib/std/crypto/phc_encoding.zig
index ccf7831550..8551e065cd 100644
--- a/lib/std/crypto/phc_encoding.zig
+++ b/lib/std/crypto/phc_encoding.zig
@@ -197,12 +197,9 @@ pub fn serialize(params: anytype, str: []u8) Error![]const u8 {
 /// Compute the number of bytes required to serialize `params`
 pub fn calcSize(params: anytype) usize {
     var trash: [128]u8 = undefined;
-    var bw: Writer = .{
-        .unbuffered_writer = .discarding,
-        .buffer = &trash,
-    };
-    serializeTo(params, &bw) catch unreachable;
-    return bw.count;
+    var w: Writer = .discarding(&trash);
+    serializeTo(params, &w) catch unreachable;
+    return w.count;
 }
 
 fn serializeTo(params: anytype, out: *Writer) !void {
diff --git a/lib/std/crypto/sha2.zig b/lib/std/crypto/sha2.zig
index 4ea2714973..8e74fe7899 100644
--- a/lib/std/crypto/sha2.zig
+++ b/lib/std/crypto/sha2.zig
@@ -383,22 +383,19 @@ fn Sha2x32(comptime iv: Iv32, digest_bits: comptime_int) type {
             for (&d.s, v) |*dv, vv| dv.* +%= vv;
         }
 
-        pub fn writable(this: *@This(), buffer: []u8) Writer {
+        pub fn writer(this: *@This(), buffer: []u8) Writer {
             return .{
-                .unbuffered_writer = .{
-                    .context = this,
-                    .vtable = &.{
-                        .writeSplat = writeSplat,
-                        .writeFile = Writer.unimplementedWriteFile,
-                    },
-                },
+                .context = this,
+                .vtable = &.{ .drain = drain },
                 .buffer = buffer,
             };
         }
 
-        fn writeSplat(context: ?*anyopaque, data: []const []const u8, splat: usize) Writer.Error!usize {
-            const this: *@This() = @ptrCast(@alignCast(context));
+        fn drain(w: *Writer, data: []const []const u8, splat: usize) Writer.Error!usize {
+            const this: *@This() = @ptrCast(@alignCast(w.context));
             const start_total = this.total_len;
+            this.update(w.buffered());
+            w.end = 0;
             for (data[0 .. data.len - 1]) |slice| this.update(slice);
             for (0..splat) |_| this.update(data[data.len - 1]);
             return @intCast(this.total_len - start_total);
diff --git a/lib/std/fmt.zig b/lib/std/fmt.zig
index 6e6e710f1f..b731ea87ad 100644
--- a/lib/std/fmt.zig
+++ b/lib/std/fmt.zig
@@ -845,14 +845,11 @@ pub fn bufPrintZ(buf: []u8, comptime fmt: []const u8, args: anytype) BufPrintErr
 /// Count the characters needed for format.
 pub fn count(comptime fmt: []const u8, args: anytype) usize {
     var trash_buffer: [64]u8 = undefined;
-    var bw: Writer = .{
-        .unbuffered_writer = .discarding,
-        .buffer = &trash_buffer,
-    };
-    bw.print(fmt, args) catch |err| switch (err) {
+    var w: Writer = .discarding(&trash_buffer);
+    w.print(fmt, args) catch |err| switch (err) {
         error.WriteFailed => unreachable,
     };
-    return bw.count;
+    return w.count;
 }
 
 pub fn allocPrint(gpa: Allocator, comptime fmt: []const u8, args: anytype) Allocator.Error![]u8 {
diff --git a/lib/std/io/Writer.zig b/lib/std/io/Writer.zig
index d2d890802a..7e06119aba 100644
--- a/lib/std/io/Writer.zig
+++ b/lib/std/io/Writer.zig
@@ -155,11 +155,7 @@ pub fn writeSplat(w: *Writer, data: []const []const u8, splat: usize) Error!usiz
     assert(data.len > 0);
     const buffer = w.buffer;
     const count = countSplat(0, data, splat);
-    if (w.end + count > buffer.len) {
-        const end = w.end;
-        const n = try w.vtable.drain(w, data, splat);
-        return n -| end;
-    }
+    if (w.end + count > buffer.len) return w.vtable.drain(w, data, splat);
     w.count += count;
     for (data) |bytes| {
         @memcpy(buffer[w.end..][0..bytes.len], bytes);
@@ -168,7 +164,6 @@ pub fn writeSplat(w: *Writer, data: []const []const u8, splat: usize) Error!usiz
     const pattern = data[data.len - 1];
     if (splat == 0) {
         @branchHint(.unlikely);
-        // It was added in the loop above; undo it here.
         w.end -= pattern.len;
         return count;
     }
@@ -245,24 +240,14 @@ pub fn writableSlice(w: *Writer, len: usize) Error![]u8 {
 /// If `minimum_length` is zero, this is equivalent to `unusedCapacitySlice`.
 pub fn writableSliceGreedy(w: *Writer, minimum_length: usize) Error![]u8 {
     assert(w.buffer.len >= minimum_length);
-    const cap_slice = w.buffer[w.end..];
-    if (cap_slice.len >= minimum_length) {
-        @branchHint(.likely);
-        return cap_slice;
+    while (true) {
+        const cap_slice = w.buffer[w.end..];
+        if (cap_slice.len >= minimum_length) {
+            @branchHint(.likely);
+            return cap_slice;
+        }
+        assert(0 == try w.vtable.drain(w, &.{""}, 1));
     }
-    const buffer = w.buffer[0..w.end];
-    const n = try w.unbuffered_writer.writeVec(&.{buffer});
-    if (n == buffer.len) {
-        @branchHint(.likely);
-        w.end = 0;
-        return w.buffer;
-    }
-    if (n > 0) {
-        const remainder = buffer[n..];
-        std.mem.copyForwards(u8, buffer[0..remainder.len], remainder);
-        w.end = remainder.len;
-    }
-    return w.buffer[w.end..];
 }
 
 pub fn ensureUnusedCapacity(w: *Writer, n: usize) Error!void {
@@ -358,39 +343,17 @@ pub fn print(w: *Writer, comptime format: []const u8, args: anytype) Error!void
 }
 
 pub fn writeByte(w: *Writer, byte: u8) Error!void {
-    const buffer = w.buffer[0..w.end];
-    if (buffer.len < w.buffer.len) {
+    while (w.buffer.len - w.end == 0) {
+        const n = try w.vtable.drain(w, &.{&.{byte}}, 1);
+        if (n > 0) {
+            w.count += 1;
+            return;
+        }
+    } else {
         @branchHint(.likely);
-        buffer.ptr[buffer.len] = byte;
-        w.end = buffer.len + 1;
+        w.buffer[w.end] = byte;
+        w.end += 1;
         w.count += 1;
-        return;
-    }
-    var buffers: [2][]const u8 = .{ buffer, &.{byte} };
-    while (true) {
-        const n = try w.unbuffered_writer.writeVec(&buffers);
-        if (n == 0) {
-            @branchHint(.unlikely);
-            continue;
-        }
-        w.count += 1;
-        if (n >= buffer.len) {
-            @branchHint(.likely);
-            if (n > buffer.len) {
-                @branchHint(.likely);
-                w.end = 0;
-                return;
-            } else {
-                buffer[0] = byte;
-                w.end = 1;
-                return;
-            }
-        }
-        const remainder = buffer[n..];
-        std.mem.copyForwards(u8, buffer[0..remainder.len], remainder);
-        buffer[remainder.len] = byte;
-        w.end = remainder.len + 1;
-        return;
     }
 }
 
diff --git a/lib/std/zon/stringify.zig b/lib/std/zon/stringify.zig
index e5d964826b..d1cfea266d 100644
--- a/lib/std/zon/stringify.zig
+++ b/lib/std/zon/stringify.zig
@@ -1040,11 +1040,8 @@ pub const Serializer = struct {
 };
 
 test Serializer {
-    var bw: Writer = .{
-        .unbuffered_writer = .discarding,
-        .buffer = &.{},
-    };
-    var s: Serializer = .{ .writer = &bw };
+    var w: Writer = .discarding(&.{});
+    var s: Serializer = .{ .writer = &w };
     var vec2 = try s.beginStruct(.{});
     try vec2.field("x", 1.5, .{});
     try vec2.fieldPrefix("prefix");