diff --git a/libc/test/src/threads/cnd_test.cpp b/libc/test/src/threads/cnd_test.cpp
--- a/libc/test/src/threads/cnd_test.cpp
+++ b/libc/test/src/threads/cnd_test.cpp
@@ -41,7 +41,7 @@
 
 int broadcast_thread_func(void *) {
   __llvm_libc::mtx_lock(&broadcast_mtx);
-  int oldval = broadcast_count.fetch_add(1);
+  unsigned oldval = broadcast_count.fetch_add(1);
   if (oldval == THRD_COUNT - 1) {
     __llvm_libc::mtx_lock(&threads_ready_mtx);
     __llvm_libc::cnd_signal(&threads_ready_cnd);
diff --git a/libc/utils/testutils/ExecuteFunction.h b/libc/utils/testutils/ExecuteFunction.h
--- a/libc/utils/testutils/ExecuteFunction.h
+++ b/libc/utils/testutils/ExecuteFunction.h
@@ -24,7 +24,7 @@
   int platform_defined;
   const char *failure = nullptr;
 
-  static constexpr uintptr_t TIMEOUT = -1L;
+  static constexpr unsigned TIMEOUT = ~0U;
 
   static ProcessStatus error(const char *error) { return {0, error}; }
   static ProcessStatus timed_out_ps() {
@@ -41,7 +41,7 @@
 };
 
 ProcessStatus invoke_in_subprocess(FunctionCaller *func,
-                                   unsigned timeout_ms = -1);
+                                   unsigned timeout_ms = TIMEOUT);
 
 const char *signal_as_string(int signum);