diff --git a/build.zig b/build.zig
index c2958e3..d253b95 100644
--- a/build.zig
+++ b/build.zig
@@ -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);