diff --git a/AnyReadable.zig b/AnyReadable.zig
index b7d0b952a957f0cb14604248a554cde60d3008d8..b649e3e5c62b1fbf5d9c114e296f0142e84df07d 100644
--- a/AnyReadable.zig
+++ b/AnyReadable.zig
@@ -10,8 +10,8 @@ state: *allowzero anyopaque,
 
 pub const Error = ReadError; // std compat
 pub const ReadError = anyerror;
-pub usingnamespace nio.Readable(@This(), ._var);
-pub fn read(r: *AnyReadable, buffer: []u8) !usize {
+pub usingnamespace nio.Readable(@This(), ._const);
+pub fn read(r: AnyReadable, buffer: []u8) !usize {
     return r.vtable.read(r.state, buffer);
 }
 pub fn anyReadable(r: AnyReadable) AnyReadable {
diff --git a/AnyWritable.zig b/AnyWritable.zig
index 258967bfc742463dd79d4f70a3738a68e862e818..0ffd3d97ccc19aa732368aff013253b2af593488 100644
--- a/AnyWritable.zig
+++ b/AnyWritable.zig
@@ -9,8 +9,8 @@ vtable: *const struct {
 state: *allowzero anyopaque,
 
 pub const WriteError = anyerror;
-pub usingnamespace nio.Writable(@This(), ._var);
-pub fn write(r: *AnyWritable, buffer: []u8) !usize {
+pub usingnamespace nio.Writable(@This(), ._const);
+pub fn write(r: AnyWritable, buffer: []const u8) !usize {
     return r.vtable.write(r.state, buffer);
 }
 pub fn anyWritable(r: AnyWritable) AnyWritable {