diff --git a/example/Socket.zig b/example/Socket.zig
index 3349136..c521cdf 100644
--- a/example/Socket.zig
+++ b/example/Socket.zig
@@ -54,7 +54,7 @@ pub const Reader = struct {
 
     fn stream(r: *Io.Reader, w: *Io.Writer, limit: Io.Limit) Io.Reader.StreamError!usize {
         const self: *Reader = @fieldParentPtr("interface", r);
-        const buf = limit.slice(w.unusedCapacitySlice());
+        const buf = limit.slice(try w.writableSliceGreedy(1));
 
         while (true) {
             var iov: [1]posix.iovec = .{
diff --git a/src/connection.zig b/src/connection.zig
index 22832a7..0757a80 100644
--- a/src/connection.zig
+++ b/src/connection.zig
@@ -253,7 +253,8 @@ pub const Connection = struct {
 
         fn stream(r: *Io.Reader, w: *Io.Writer, limit: Io.Limit) Io.Reader.StreamError!usize {
             const self: *Reader = @fieldParentPtr("interface", r);
-            const n = self.conn.read(limit.slice(w.unusedCapacitySlice())) catch |err| {
+            const buf = limit.slice(try w.writableSliceGreedy(1));
+            const n = self.conn.read(buf) catch |err| {
                 self.err = err;
                 if (err == error.EndOfStream) return error.EndOfStream;
                 return error.ReadFailed;