diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6dbdf0c93e..d9824e5c12 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -387,6 +387,18 @@ set(ZIG_STAGE2_SOURCES
     lib/std/Build.zig
     lib/std/Build/Cache.zig
     lib/std/Build/Cache/DepTokenizer.zig
+    lib/std/Io.zig
+    lib/std/Io/Reader.zig
+    lib/std/Io/Writer.zig
+    lib/std/Io/buffered_atomic_file.zig
+    lib/std/Io/buffered_writer.zig
+    lib/std/Io/change_detection_stream.zig
+    lib/std/Io/counting_reader.zig
+    lib/std/Io/counting_writer.zig
+    lib/std/Io/find_byte_writer.zig
+    lib/std/Io/fixed_buffer_stream.zig
+    lib/std/Io/limited_reader.zig
+    lib/std/Io/seekable_stream.zig
     lib/std/Progress.zig
     lib/std/Random.zig
     lib/std/Target.zig
@@ -448,9 +460,6 @@ set(ZIG_STAGE2_SOURCES
     lib/std/hash_map.zig
     lib/std/heap.zig
     lib/std/heap/arena_allocator.zig
-    lib/std/io.zig
-    lib/std/io/Reader.zig
-    lib/std/io/Writer.zig
     lib/std/json.zig
     lib/std/leb128.zig
     lib/std/log.zig
diff --git a/lib/std/io.zig b/lib/std/Io.zig
similarity index 98%
rename from lib/std/io.zig
rename to lib/std/Io.zig
index d27338fe5f..90b1ea7617 100644
--- a/lib/std/io.zig
+++ b/lib/std/Io.zig
@@ -79,13 +79,13 @@ pub const Limit = enum(usize) {
     }
 };
 
-pub const Reader = @import("io/Reader.zig");
-pub const Writer = @import("io/Writer.zig");
+pub const Reader = @import("Io/Reader.zig");
+pub const Writer = @import("Io/Writer.zig");
 
-pub const ChangeDetectionStream = @import("io/change_detection_stream.zig").ChangeDetectionStream;
-pub const changeDetectionStream = @import("io/change_detection_stream.zig").changeDetectionStream;
+pub const ChangeDetectionStream = @import("Io/change_detection_stream.zig").ChangeDetectionStream;
+pub const changeDetectionStream = @import("Io/change_detection_stream.zig").changeDetectionStream;
 
-pub const tty = @import("io/tty.zig");
+pub const tty = @import("Io/tty.zig");
 
 pub fn poll(
     gpa: Allocator,
@@ -495,5 +495,5 @@ pub fn PollFiles(comptime StreamEnum: type) type {
 test {
     _ = Reader;
     _ = Writer;
-    _ = @import("io/test.zig");
+    _ = @import("Io/test.zig");
 }
diff --git a/lib/std/io/DeprecatedReader.zig b/lib/std/Io/DeprecatedReader.zig
similarity index 100%
rename from lib/std/io/DeprecatedReader.zig
rename to lib/std/Io/DeprecatedReader.zig
diff --git a/lib/std/io/DeprecatedWriter.zig b/lib/std/Io/DeprecatedWriter.zig
similarity index 100%
rename from lib/std/io/DeprecatedWriter.zig
rename to lib/std/Io/DeprecatedWriter.zig
diff --git a/lib/std/io/Reader.zig b/lib/std/Io/Reader.zig
similarity index 100%
rename from lib/std/io/Reader.zig
rename to lib/std/Io/Reader.zig
diff --git a/lib/std/io/Reader/Limited.zig b/lib/std/Io/Reader/Limited.zig
similarity index 100%
rename from lib/std/io/Reader/Limited.zig
rename to lib/std/Io/Reader/Limited.zig
diff --git a/lib/std/io/Writer.zig b/lib/std/Io/Writer.zig
similarity index 100%
rename from lib/std/io/Writer.zig
rename to lib/std/Io/Writer.zig
diff --git a/lib/std/io/change_detection_stream.zig b/lib/std/Io/change_detection_stream.zig
similarity index 100%
rename from lib/std/io/change_detection_stream.zig
rename to lib/std/Io/change_detection_stream.zig
diff --git a/lib/std/io/find_byte_writer.zig b/lib/std/Io/find_byte_writer.zig
similarity index 100%
rename from lib/std/io/find_byte_writer.zig
rename to lib/std/Io/find_byte_writer.zig
diff --git a/lib/std/io/test.zig b/lib/std/Io/test.zig
similarity index 100%
rename from lib/std/io/test.zig
rename to lib/std/Io/test.zig
diff --git a/lib/std/io/tty.zig b/lib/std/Io/tty.zig
similarity index 100%
rename from lib/std/io/tty.zig
rename to lib/std/Io/tty.zig
diff --git a/lib/std/debug.zig b/lib/std/debug.zig
index 00a9606f53..06b6cec887 100644
--- a/lib/std/debug.zig
+++ b/lib/std/debug.zig
@@ -219,13 +219,16 @@ pub fn unlockStderrWriter() void {
     std.Progress.unlockStderrWriter();
 }
 
-/// Print to stderr, unbuffered, and silently returning on failure. Intended
-/// for use in "printf debugging". Use `std.log` functions for proper logging.
+/// Print to stderr, silently returning on failure. Intended for use in "printf
+/// debugging". Use `std.log` functions for proper logging.
+///
+/// Uses a 64-byte buffer for formatted printing which is flushed before this
+/// function returns.
 pub fn print(comptime fmt: []const u8, args: anytype) void {
-    var buffer: [32]u8 = undefined;
-    const bw = lockStderrWriter(&buffer);
+    var buffer: [64]u8 = undefined;
+    const w = lockStderrWriter(&buffer);
     defer unlockStderrWriter();
-    nosuspend bw.print(fmt, args) catch return;
+    nosuspend w.print(fmt, args) catch return;
 }
 
 pub fn getStderrMutex() *std.Thread.Mutex {
diff --git a/lib/std/fs/path.zig b/lib/std/fs/path.zig
index 1cf4dc3c64..542166b78e 100644
--- a/lib/std/fs/path.zig
+++ b/lib/std/fs/path.zig
@@ -227,8 +227,8 @@ test join {
         try testJoinMaybeZWindows(&[_][]const u8{ "c:\\a\\", "b\\", "c" }, "c:\\a\\b\\c", zero);
 
         try testJoinMaybeZWindows(
-            &[_][]const u8{ "c:\\home\\andy\\dev\\zig\\build\\lib\\zig\\std", "io.zig" },
-            "c:\\home\\andy\\dev\\zig\\build\\lib\\zig\\std\\io.zig",
+            &[_][]const u8{ "c:\\home\\andy\\dev\\zig\\build\\lib\\zig\\std", "ab.zig" },
+            "c:\\home\\andy\\dev\\zig\\build\\lib\\zig\\std\\ab.zig",
             zero,
         );
 
@@ -252,8 +252,8 @@ test join {
         try testJoinMaybeZPosix(&[_][]const u8{ "/a/", "b/", "c" }, "/a/b/c", zero);
 
         try testJoinMaybeZPosix(
-            &[_][]const u8{ "/home/andy/dev/zig/build/lib/zig/std", "io.zig" },
-            "/home/andy/dev/zig/build/lib/zig/std/io.zig",
+            &[_][]const u8{ "/home/andy/dev/zig/build/lib/zig/std", "ab.zig" },
+            "/home/andy/dev/zig/build/lib/zig/std/ab.zig",
             zero,
         );
 
diff --git a/lib/std/log.zig b/lib/std/log.zig
index 5bfb812bf3..417d2e1ced 100644
--- a/lib/std/log.zig
+++ b/lib/std/log.zig
@@ -136,8 +136,11 @@ pub fn defaultLogEnabled(comptime message_level: Level) bool {
     return comptime logEnabled(message_level, default_log_scope);
 }
 
-/// The default implementation for the log function, custom log functions may
+/// The default implementation for the log function. Custom log functions may
 /// forward log messages to this function.
+///
+/// Uses a 64-byte buffer for formatted printing which is flushed before this
+/// function returns.
 pub fn defaultLog(
     comptime message_level: Level,
     comptime scope: @Type(.enum_literal),
@@ -146,7 +149,7 @@ pub fn defaultLog(
 ) void {
     const level_txt = comptime message_level.asText();
     const prefix2 = if (scope == .default) ": " else "(" ++ @tagName(scope) ++ "): ";
-    var buffer: [32]u8 = undefined;
+    var buffer: [64]u8 = undefined;
     const stderr = std.debug.lockStderrWriter(&buffer);
     defer std.debug.unlockStderrWriter();
     nosuspend stderr.print(level_txt ++ prefix2 ++ format ++ "\n", args) catch return;
diff --git a/lib/std/std.zig b/lib/std/std.zig
index 73a29ed28e..ba260ff503 100644
--- a/lib/std/std.zig
+++ b/lib/std/std.zig
@@ -25,6 +25,7 @@ pub const EnumMap = enums.EnumMap;
 pub const EnumSet = enums.EnumSet;
 pub const HashMap = hash_map.HashMap;
 pub const HashMapUnmanaged = hash_map.HashMapUnmanaged;
+pub const Io = @import("Io.zig");
 pub const MultiArrayList = @import("multi_array_list.zig").MultiArrayList;
 pub const PriorityQueue = @import("priority_queue.zig").PriorityQueue;
 pub const PriorityDequeue = @import("priority_dequeue.zig").PriorityDequeue;
@@ -65,7 +66,8 @@ pub const hash = @import("hash.zig");
 pub const hash_map = @import("hash_map.zig");
 pub const heap = @import("heap.zig");
 pub const http = @import("http.zig");
-pub const io = @import("io.zig");
+/// Deprecated
+pub const io = Io;
 pub const json = @import("json.zig");
 pub const leb = @import("leb128.zig");
 pub const log = @import("log.zig");