diff --git a/json.zig b/json.zig
index 490ee0f97c1deda7bd5d675880551f9a9913664c..82e03a59bbf5f2a8612b512ddf4c0023b498655f 100644
--- a/json.zig
+++ b/json.zig
@@ -3,20 +3,21 @@ const string = []const u8;
 const extras = @import("extras");
 const tracer = @import("tracer");
 const intrusive_parser = @import("intrusive-parser");
+const nio = @import("nio");
 
 pub const Error = error{ OutOfMemory, EndOfStream, MalformedJson };
 pub const ObjectHashMap = std.AutoArrayHashMapUnmanaged(StringIndex, ValueIndex);
 
-pub fn parse(alloc: std.mem.Allocator, path: string, inreader: anytype, options: Parser.Options) (@TypeOf(inreader).Error || Error)!Document {
+pub fn parse(alloc: std.mem.Allocator, path: string, inreadable: anytype, options: Parser.Options) (Instance(@TypeOf(inreadable)).ReadError || Error)!Document {
     const t = tracer.trace(@src(), "", .{});
     defer t.end();
 
     _ = path;
 
-    var p = try Parser.init(alloc, inreader.any(), options);
+    var p = try Parser.init(alloc, inreadable.anyReadable(), options);
     defer p.deinit();
 
-    const root = try parseElementPrecise(alloc, &p, @TypeOf(inreader).Error || Error);
+    const root = try parseElementPrecise(alloc, &p, Instance(@TypeOf(inreadable)).ReadError || Error);
     if (p.parser.avail() > 0) return error.MalformedJson;
     const data = try p.parser.data.toOwnedSlice(alloc);
 
@@ -26,9 +27,16 @@ pub fn parse(alloc: std.mem.Allocator, path: string, inreader: anytype, options:
     };
 }
 
+fn Instance(T: type) type {
+    return switch (@typeInfo(T)) {
+        .pointer => |info| info.child,
+        else => T,
+    };
+}
+
 pub fn parseFromSlice(alloc: std.mem.Allocator, path: string, input: string, options: Parser.Options) !Document {
-    var fbs = std.io.fixedBufferStream(input);
-    return parse(alloc, path, fbs.reader(), options);
+    var fbs: nio.FixedBufferStream(string) = .init(input);
+    return parse(alloc, path, &fbs, options);
 }
 
 fn parseElementPrecise(alloc: std.mem.Allocator, p: *Parser, comptime E: type) E!ValueIndex {
@@ -253,7 +261,7 @@ pub const Parser = struct {
     support_trailing_commas: bool,
     maximum_depth: u16,
 
-    pub fn init(allocator: std.mem.Allocator, any: std.io.AnyReader, options: Options) !Parser {
+    pub fn init(allocator: std.mem.Allocator, any: nio.AnyReadable, options: Options) !Parser {
         var p: Parser = .{
             .parser = intrusive_parser.Parser.init(allocator, any, @intFromEnum(Value.Tag.string)),
             .support_trailing_commas = options.support_trailing_commas,
diff --git a/licenses.txt b/licenses.txt
index f415640d57e86e1738bc259f0f6704ad7b3697ad..7e7cebea43063578ffec120d3211b0e5976b0302 100644
--- a/licenses.txt
+++ b/licenses.txt
@@ -1,10 +1,18 @@
 MIT:
 = https://spdx.org/licenses/MIT
 - This
+- git https://github.com/nektro/zig-errno
 - git https://github.com/nektro/zig-extras
+- git https://github.com/nektro/zig-libc
+- git https://github.com/nektro/zig-sys-libc
 - git https://github.com/nektro/zig-tracer
 - git https://github.com/nst/JSONTestSuite
 
 MPL-2.0:
 = https://spdx.org/licenses/MPL-2.0
 - git https://github.com/nektro/zig-intrusive-parser
+- git https://github.com/nektro/zig-nfs
+- git https://github.com/nektro/zig-nio
+
+Unspecified:
+- system_lib c
diff --git a/test.zig b/test.zig
index 417cbf2125442c6ecfe6f9bbbfd2773134de3a80..136eebf871e6267421133b9e9e2adca7dc362da8 100644
--- a/test.zig
+++ b/test.zig
@@ -1,12 +1,15 @@
 const std = @import("std");
 const json = @import("json");
 const build_options = @import("build_options");
+const nfs = @import("nfs");
+const nio = @import("nio");
+
 const JSONTestSuite_root = build_options.JSONTestSuite_root;
 
 fn parse_full(buffer: []const u8) !void {
     const alloc = std.testing.allocator;
-    var fbs = std.io.fixedBufferStream(buffer);
-    var doc = try json.parse(alloc, "", fbs.reader(), .{ .support_trailing_commas = true, .maximum_depth = 100 });
+    var fbs: nio.FixedBufferStream([]const u8) = .init(buffer);
+    var doc = try json.parse(alloc, "", &fbs, .{ .support_trailing_commas = true, .maximum_depth = 100 });
     defer doc.deinit(alloc);
 }
 
@@ -260,11 +263,11 @@ test {
     );
 }
 
-fn expectPass(path: []const u8) !void {
+fn expectPass(path: [:0]const u8) !void {
     const alloc = std.testing.allocator;
-    var file = try std.fs.cwd().openFile(path, .{});
+    const file = try nfs.cwd().openFile(path, .{});
     defer file.close();
-    var doc = try json.parse(alloc, path, file.reader(), .{ .support_trailing_commas = false, .maximum_depth = 100 });
+    var doc = try json.parse(alloc, path, file, .{ .support_trailing_commas = false, .maximum_depth = 100 });
     defer doc.deinit(alloc);
 }
 
@@ -366,11 +369,11 @@ test { try expectPass(JSONTestSuite_root ++ "/y_structure_true_in_array.json");
 test { try expectPass(JSONTestSuite_root ++ "/y_structure_whitespace_array.json"); }
 // zig fmt: on
 
-fn expectFail(path: []const u8) !void {
+fn expectFail(path: [:0]const u8) !void {
     const alloc = std.testing.allocator;
-    var file = try std.fs.cwd().openFile(path, .{});
+    const file = try nfs.cwd().openFile(path, .{});
     defer file.close();
-    var doc = json.parse(alloc, path, file.reader(), .{ .support_trailing_commas = false, .maximum_depth = 100 }) catch return;
+    var doc = json.parse(alloc, path, file, .{ .support_trailing_commas = false, .maximum_depth = 100 }) catch return;
     defer doc.deinit(alloc);
     try std.testing.expect(false);
 }
@@ -568,8 +571,8 @@ test { try expectFail(JSONTestSuite_root ++ "/n_structure_whitespace_U+2060_word
 
 fn expectCanonical(buffer: []const u8) !void {
     const alloc = std.testing.allocator;
-    var fbs = std.io.fixedBufferStream(buffer);
-    var doc = try json.parse(alloc, "", fbs.reader(), .{ .support_trailing_commas = true, .maximum_depth = 100 });
+    var fbs: nio.FixedBufferStream([]const u8) = .init(buffer);
+    var doc = try json.parse(alloc, "", &fbs, .{ .support_trailing_commas = true, .maximum_depth = 100 });
     defer doc.deinit(alloc);
     doc.acquire();
     defer doc.release();
@@ -589,10 +592,10 @@ test { try expectCanonical("[7,8,9]"); }
 
 test {
     const alloc = std.testing.allocator;
-    var fbs = std.io.fixedBufferStream(
+    var fbs: nio.FixedBufferStream([]const u8) = .init(
         \\["abc",456,"ghi",{"foo":"bar"}]
     );
-    var doc = try json.parse(alloc, "", fbs.reader(), .{ .support_trailing_commas = true, .maximum_depth = 100 });
+    var doc = try json.parse(alloc, "", &fbs, .{ .support_trailing_commas = true, .maximum_depth = 100 });
     defer doc.deinit(alloc);
     doc.acquire();
     defer doc.release();
diff --git a/zig.mod b/zig.mod
index 98d91ebac3b175c9e1e79641748f42a45da7071e..a5d8b52c51b189fcb237c2f92ec4cd2480394518 100644
--- a/zig.mod
+++ b/zig.mod
@@ -7,8 +7,11 @@ dependencies:
   - src: git https://github.com/nektro/zig-extras
   - src: git https://github.com/nektro/zig-tracer
   - src: git https://github.com/nektro/zig-intrusive-parser
+  - src: git https://github.com/nektro/zig-nio
 
 root_dependencies:
+  - src: git https://github.com/nektro/zig-nio
+  - src: git https://github.com/nektro/zig-nfs
   - src: git https://github.com/nst/JSONTestSuite commit-984defc2deaa653cb73cd29f4144a720ec9efe7c
     id: bebdygynna6kk8zbbprkva6yd28x9wmf57vtzxjn
     license: MIT