diff --git a/libc/test/UnitTest/ExecuteFunctionUnix.cpp b/libc/test/UnitTest/ExecuteFunctionUnix.cpp
index 3a657c00851c7b..df71738668592a 100644
--- a/libc/test/UnitTest/ExecuteFunctionUnix.cpp
+++ b/libc/test/UnitTest/ExecuteFunctionUnix.cpp
@@ -8,13 +8,13 @@
 
 #include "ExecuteFunction.h"
 #include "src/__support/macros/config.h"
-#include <cassert>
-#include <cstdlib>
-#include <cstring>
-#include <iostream>
-#include <memory>
+#include "test/UnitTest/ExecuteFunction.h" // FunctionCaller
+#include <assert.h>
 #include <poll.h>
 #include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
@@ -35,21 +35,20 @@ int ProcessStatus::get_fatal_signal() {
 }
 
 ProcessStatus invoke_in_subprocess(FunctionCaller *func, unsigned timeout_ms) {
-  std::unique_ptr<FunctionCaller> X(func);
   int pipe_fds[2];
   if (::pipe(pipe_fds) == -1)
     return ProcessStatus::error("pipe(2) failed");
 
   // Don't copy the buffers into the child process and print twice.
-  std::cout.flush();
-  std::cerr.flush();
+  ::fflush(stderr);
+  ::fflush(stdout);
   pid_t pid = ::fork();
   if (pid == -1)
     return ProcessStatus::error("fork(2) failed");
 
   if (!pid) {
     (*func)();
-    std::exit(0);
+    ::exit(0);
   }
   ::close(pipe_fds[1]);
 
diff --git a/libc/test/UnitTest/FPExceptMatcher.cpp b/libc/test/UnitTest/FPExceptMatcher.cpp
index 37ba0a0a7abde4..889f9f6f44a913 100644
--- a/libc/test/UnitTest/FPExceptMatcher.cpp
+++ b/libc/test/UnitTest/FPExceptMatcher.cpp
@@ -9,11 +9,11 @@
 #include "FPExceptMatcher.h"
 
 #include "src/__support/macros/config.h"
+#include "test/UnitTest/ExecuteFunction.h" // FunctionCaller
 #include "test/UnitTest/Test.h"
 
 #include "hdr/types/fenv_t.h"
 #include "src/__support/FPUtil/FEnvImpl.h"
-#include <memory>
 #include <setjmp.h>
 #include <signal.h>
 
@@ -37,14 +37,13 @@ static void sigfpeHandler(int sig) {
 }
 
 FPExceptMatcher::FPExceptMatcher(FunctionCaller *func) {
-  auto oldSIGFPEHandler = signal(SIGFPE, &sigfpeHandler);
-  std::unique_ptr<FunctionCaller> funcUP(func);
+  sighandler_t oldSIGFPEHandler = signal(SIGFPE, &sigfpeHandler);
 
   caughtExcept = false;
   fenv_t oldEnv;
   fputil::get_env(&oldEnv);
   if (sigsetjmp(jumpBuffer, 1) == 0)
-    funcUP->call();
+    func->call();
   // We restore the previous floating point environment after
   // the call to the function which can potentially raise SIGFPE.
   fputil::set_env(&oldEnv);
diff --git a/libc/test/UnitTest/LibcDeathTestExecutors.cpp b/libc/test/UnitTest/LibcDeathTestExecutors.cpp
index 77b0559c7acea9..943e2c23c5fde9 100644
--- a/libc/test/UnitTest/LibcDeathTestExecutors.cpp
+++ b/libc/test/UnitTest/LibcDeathTestExecutors.cpp
@@ -12,7 +12,7 @@
 #include "test/UnitTest/ExecuteFunction.h"
 #include "test/UnitTest/TestLogger.h"
 
-#include <cassert>
+#include <assert.h>
 
 namespace {
 constexpr unsigned TIMEOUT_MS = 10000;