diff --git a/README.md b/README.md
index 5e77bd2..01f2f5e 100644
--- a/README.md
+++ b/README.md
@@ -87,6 +87,7 @@ that if you update one, you may need to also update the other.
 
 ### Version Changes
 
+* 2026-01-09 zig 0.16.0-dev.2075 - move randomness API to `std.Io`, see [#30709](https://codeberg.org/ziglang/zig/pulls/30709)
 * 2026-01-07 zig 0.16.0-dev.2040 - adjust temp files, see [#30683](https://codeberg.org/ziglang/zig/pulls/30683)
 * 2026-01-06 zig 0.16.0-dev.1976 - move process API to `std.Io` and changes to main/environ/argv, see [#30644](https://codeberg.org/ziglang/zig/pulls/30644)
 * *2025-12-28* zig 0.16.0-dev.1859 - file system I/O integrated with the std.Io interface, see [#30232](https://codeberg.org/ziglang/zig/pulls/30232)
diff --git a/build.zig b/build.zig
index c2958e3..be323c9 100644
--- a/build.zig
+++ b/build.zig
@@ -15,7 +15,7 @@ const print = std.debug.print;
 //     1) Getting Started
 //     2) Version Changes
 comptime {
-    const required_zig = "0.16.0-dev.2040";
+    const required_zig = "0.16.0-dev.2075";
     const current_zig = builtin.zig_version;
     const min_zig = std.SemanticVersion.parse(required_zig) catch unreachable;
     if (current_zig.order(min_zig) == .lt) {
@@ -206,7 +206,7 @@ pub fn build(b: *Build) !void {
 
         var prng = std.Random.DefaultPrng.init(blk: {
             var seed: u64 = undefined;
-            try std.posix.getrandom(std.mem.asBytes(&seed));
+            io.random(std.mem.asBytes(&seed));
             break :blk seed;
         });
         const rnd = prng.random();
@@ -1287,7 +1287,7 @@ const exercises = [_]Exercise{
         \\Max difference (new fn): 0.014
         ,
     },
-    .{ .main_file = "110_quiz9.zig", .output =
+    .{ .main_file = "110_quiz9.zig", .output = 
     \\Toggle pins with XOR on PORTB
     \\-----------------------------
     \\  1100 // (initial state of PORTB)
diff --git a/test/tests.zig b/test/tests.zig
index 94cf6aa..509cb54 100644
--- a/test/tests.zig
+++ b/test/tests.zig
@@ -394,7 +394,11 @@ fn heal(allocator: Allocator, exercises: []const Exercise, work_path: []const u8
 
 fn createTempPath(b: *Build) ![]const u8 {
     const io = b.graph.io;
-    const rand_int = std.crypto.random.int(u64);
+    const rand_int = r: {
+        var x: u64 = undefined;
+        io.random(@ptrCast(&x));
+        break :r x;
+    };
     const tmp_dir_sub_path = "tmp" ++ std.Io.Dir.path.sep_str ++ std.fmt.hex(rand_int);
     const result_path = b.cache_root.join(b.allocator, &.{tmp_dir_sub_path}) catch @panic("OOM");
     try b.cache_root.handle.createDirPath(io, tmp_dir_sub_path);