diff --git a/std/os/index.zig b/std/os/index.zig
index 7feaae0ff1..e472908c68 100644
--- a/std/os/index.zig
+++ b/std/os/index.zig
@@ -115,6 +115,14 @@ pub fn getRandomBytes(buf: []u8) !void {
                 };
             }
         },
+        Os.zen => {
+            const randomness = []u8 {42, 1, 7, 12, 22, 17, 99, 16, 26, 87, 41, 45};
+            var i: usize = 0;
+            while (i < buf.len) : (i += 1) {
+                if (i > randomness.len) return error.Unknown;
+                buf[i] = randomness[i];
+            }
+        },
         else => @compileError("Unsupported OS"),
     }
 }
diff --git a/std/os/zen.zig b/std/os/zen.zig
index 9e1944dc6d..51528ca391 100644
--- a/std/os/zen.zig
+++ b/std/os/zen.zig
@@ -107,14 +107,17 @@ pub fn write(fd: i32, buf: &const u8, count: usize) usize {
 ///////////////////////////
 
 pub const Syscall = enum(usize) {
-    exit         = 0,
-    createPort   = 1,
-    send         = 2,
-    receive      = 3,
-    subscribeIRQ = 4,
-    inb          = 5,
-    map          = 6,
-    createThread = 7,
+    exit          = 0,
+    createPort    = 1,
+    send          = 2,
+    receive       = 3,
+    subscribeIRQ  = 4,
+    inb           = 5,
+    map           = 6,
+    createThread  = 7,
+    createProcess = 8,
+    wait          = 9,
+    portReady     = 10,
 };
 
 
@@ -158,6 +161,17 @@ pub fn createThread(function: fn()void) u16 {
     return u16(syscall1(Syscall.createThread, @ptrToInt(function)));
 }
 
+pub fn createProcess(elf_addr: usize) u16 {
+    return u16(syscall1(Syscall.createProcess, elf_addr));
+}
+
+pub fn wait(tid: u16) void {
+    _ = syscall1(Syscall.wait, tid);
+}
+
+pub fn portReady(port: u16) bool {
+    return syscall1(Syscall.portReady, port) != 0;
+}
 
 /////////////////////////
 ////  Syscall stubs  ////
diff --git a/std/special/bootstrap.zig b/std/special/bootstrap.zig
index ad4d4891ed..d2c22c13e1 100644
--- a/std/special/bootstrap.zig
+++ b/std/special/bootstrap.zig
@@ -84,8 +84,10 @@ fn callMain() u8 {
         builtin.TypeId.ErrorUnion => {
             root.main() catch |err| {
                 std.debug.warn("error: {}\n", @errorName(err));
-                if (@errorReturnTrace()) |trace| {
-                    std.debug.dumpStackTrace(trace);
+                if (builtin.os != builtin.Os.zen) {
+                    if (@errorReturnTrace()) |trace| {
+                        std.debug.dumpStackTrace(trace);
+                    }
                 }
                 return 1;
             };