diff --git a/libc/cmake/modules/LLVMLibCTestRules.cmake b/libc/cmake/modules/LLVMLibCTestRules.cmake
--- a/libc/cmake/modules/LLVMLibCTestRules.cmake
+++ b/libc/cmake/modules/LLVMLibCTestRules.cmake
@@ -402,7 +402,6 @@
 #     SUITE <the suite to which the test should belong>
 #     SRCS <src1.cpp> [src2.cpp ...]
 #     HDRS [hdr1.cpp ...]
-#     STARTUP <fully qualified startup system target name>
 #     DEPENDS <list of entrypoint or other object targets>
 #     ARGS <list of command line arguments to be passed to the test>
 #     ENV <list of environment variables to set before running the test>
@@ -420,7 +419,7 @@
   cmake_parse_arguments(
     "INTEGRATION_TEST"
     "" # No optional arguments
-    "SUITE;STARTUP" # Single value arguments
+    "SUITE" # Single value arguments
     "SRCS;HDRS;DEPENDS;ARGS;ENV;COMPILE_OPTIONS" # Multi-value arguments
     ${ARGN}
   )
@@ -428,20 +427,20 @@
   if(NOT INTEGRATION_TEST_SUITE)
     message(FATAL_ERROR "SUITE not specified for ${fq_target_name}")
   endif()
-  if(NOT INTEGRATION_TEST_STARTUP)
-    message(FATAL_ERROR "The STARTUP to link to the integration test is missing.")
-  endif()
   if(NOT INTEGRATION_TEST_SRCS)
     message(FATAL_ERROR "The SRCS list for add_integration_test is missing.")
   endif()
+  if(NOT TARGET libc.startup.${LIBC_TARGET_OS}.crt1)
+    message(FATAL_ERROR "The 'crt1' target for the integration test is missing.")
+  endif()
 
   get_fq_target_name(${test_name}.libc fq_libc_target_name)
 
   get_fq_deps_list(fq_deps_list ${INTEGRATION_TEST_DEPENDS})
   list(APPEND fq_deps_list
-      # All integration tests need to inherit the same dependencies as the
-      # startup code.
-      ${INTEGRATION_TEST_STARTUP}
+      # All integration tests use the operating system's startup object and need
+      # to inherit the same dependencies.
+      libc.startup.${LIBC_TARGET_OS}.crt1
       # We always add the memory functions objects. This is because the
       # compiler's codegen can emit calls to the C memory functions.
       libc.src.string.bcmp
diff --git a/libc/test/integration/src/__support/threads/CMakeLists.txt b/libc/test/integration/src/__support/threads/CMakeLists.txt
--- a/libc/test/integration/src/__support/threads/CMakeLists.txt
+++ b/libc/test/integration/src/__support/threads/CMakeLists.txt
@@ -11,8 +11,6 @@
     libc-support-threads-integration-tests
   SRCS
     thread_detach_test.cpp
-  STARTUP
-    libc.startup.linux.crt1
   DEPENDS
     libc.src.__support.threads.mutex
     libc.src.__support.threads.thread
@@ -24,8 +22,6 @@
     libc-support-threads-integration-tests
   SRCS
     thread_tls_test.cpp
-  STARTUP
-    libc.startup.linux.crt1
   DEPENDS
     libc.src.__support.threads.thread
 )
diff --git a/libc/test/integration/src/pthread/CMakeLists.txt b/libc/test/integration/src/pthread/CMakeLists.txt
--- a/libc/test/integration/src/pthread/CMakeLists.txt
+++ b/libc/test/integration/src/pthread/CMakeLists.txt
@@ -6,8 +6,6 @@
     libc-pthread-integration-tests
   SRCS
     pthread_mutex_test.cpp
-  STARTUP
-    libc.startup.linux.crt1
   DEPENDS
     libc.include.pthread
     libc.src.errno.errno
@@ -25,8 +23,6 @@
     libc-pthread-integration-tests
   SRCS
     pthread_test.cpp
-  STARTUP
-    libc.startup.linux.crt1
   DEPENDS
     libc.include.pthread
     libc.src.pthread.pthread_create
@@ -39,8 +35,6 @@
     libc-pthread-integration-tests
   SRCS
     pthread_equal_test.cpp
-  STARTUP
-    libc.startup.linux.crt1
   DEPENDS
     libc.include.pthread
     libc.src.errno.errno
@@ -60,8 +54,6 @@
     libc-pthread-integration-tests
   SRCS
     pthread_name_test.cpp
-  STARTUP
-    libc.startup.linux.crt1
   DEPENDS
     libc.include.errno
     libc.include.pthread
@@ -83,8 +75,6 @@
     libc-pthread-integration-tests
   SRCS
     pthread_exit_test.cpp
-  STARTUP
-    libc.startup.linux.crt1
   DEPENDS
     libc.include.pthread
     libc.src.pthread.pthread_create
@@ -98,8 +88,6 @@
     libc-pthread-integration-tests
   SRCS
     pthread_tss_test.cpp
-  STARTUP
-    libc.startup.linux.crt1
   DEPENDS
     libc.include.pthread
     libc.src.pthread.pthread_create
@@ -117,8 +105,6 @@
     libc-pthread-integration-tests
   SRCS
     pthread_once_test.cpp
-  STARTUP
-    libc.startup.linux.crt1
   DEPENDS
     libc.include.pthread
     libc.src.pthread.pthread_once
diff --git a/libc/test/integration/src/spawn/CMakeLists.txt b/libc/test/integration/src/spawn/CMakeLists.txt
--- a/libc/test/integration/src/spawn/CMakeLists.txt
+++ b/libc/test/integration/src/spawn/CMakeLists.txt
@@ -26,8 +26,6 @@
     spawn-integration-tests
   SRCS
     posix_spawn_test.cpp
-  STARTUP
-    libc.startup.linux.crt1
   DEPENDS
     libc_posix_spawn_test_binary
     libc.test.integration.src.spawn.test_binary_properties
diff --git a/libc/test/integration/src/stdio/CMakeLists.txt b/libc/test/integration/src/stdio/CMakeLists.txt
--- a/libc/test/integration/src/stdio/CMakeLists.txt
+++ b/libc/test/integration/src/stdio/CMakeLists.txt
@@ -9,8 +9,6 @@
     stdio-integration-tests
   SRCS
     sprintf_size_test.cpp
-  STARTUP
-    libc.startup.linux.crt1
   DEPENDS
     libc.src.stdio.sprintf
   ARGS
@@ -26,8 +24,6 @@
     stdio-integration-tests
   SRCS
     sprintf_size_test.cpp
-  STARTUP
-    libc.startup.linux.crt1
   ARGS
     "%s %c %d"
     "First arg"
diff --git a/libc/test/integration/src/stdlib/CMakeLists.txt b/libc/test/integration/src/stdlib/CMakeLists.txt
--- a/libc/test/integration/src/stdlib/CMakeLists.txt
+++ b/libc/test/integration/src/stdlib/CMakeLists.txt
@@ -7,8 +7,6 @@
     stdlib-integration-tests
   SRCS
     getenv_test.cpp
-  STARTUP
-    libc.startup.linux.crt1
   DEPENDS
     libc.src.stdlib.getenv
   ENV
diff --git a/libc/test/integration/src/threads/CMakeLists.txt b/libc/test/integration/src/threads/CMakeLists.txt
--- a/libc/test/integration/src/threads/CMakeLists.txt
+++ b/libc/test/integration/src/threads/CMakeLists.txt
@@ -6,8 +6,6 @@
     libc-threads-integration-tests
   SRCS
     mtx_test.cpp
-  STARTUP
-    libc.startup.linux.crt1
   DEPENDS
     libc.include.threads
     libc.src.errno.errno
@@ -25,8 +23,6 @@
     libc-threads-integration-tests
   SRCS
     thrd_equal_test.cpp
-  STARTUP
-    libc.startup.linux.crt1
   DEPENDS
     libc.include.threads
     libc.src.threads.mtx_destroy
@@ -45,8 +41,6 @@
     libc-threads-integration-tests
   SRCS
     thrd_test.cpp
-  STARTUP
-    libc.startup.linux.crt1
   DEPENDS
     libc.include.threads
     libc.src.errno.errno
@@ -60,8 +54,6 @@
     libc-threads-integration-tests
   SRCS
     thrd_exit_test.cpp
-  STARTUP
-    libc.startup.linux.crt1
   DEPENDS
     libc.include.threads
     libc.src.threads.thrd_create
@@ -75,8 +67,6 @@
     libc-threads-integration-tests
   SRCS
     tss_test.cpp
-  STARTUP
-    libc.startup.linux.crt1
   DEPENDS
     libc.include.threads
     libc.src.threads.thrd_create
@@ -94,8 +84,6 @@
     libc-threads-integration-tests
   SRCS
     call_once_test.cpp
-  STARTUP
-    libc.startup.linux.crt1
   DEPENDS
     libc.include.threads
     libc.src.threads.call_once
@@ -114,8 +102,6 @@
     libc-threads-integration-tests
   SRCS
     cnd_test.cpp
-  STARTUP
-    libc.startup.linux.crt1
   DEPENDS
     libc.include.threads
     libc.src.threads.cnd_init
diff --git a/libc/test/integration/src/unistd/CMakeLists.txt b/libc/test/integration/src/unistd/CMakeLists.txt
--- a/libc/test/integration/src/unistd/CMakeLists.txt
+++ b/libc/test/integration/src/unistd/CMakeLists.txt
@@ -7,8 +7,6 @@
     unistd-integration-tests
   SRCS
     getcwd_test.cpp
-  STARTUP
-    libc.startup.linux.crt1
   DEPENDS
     libc.src.__support.CPP.string_view
     libc.src.errno.errno
@@ -22,8 +20,6 @@
     unistd-integration-tests
   SRCS
     fork_test.cpp
-  STARTUP
-    libc.startup.linux.crt1
   DEPENDS
     libc.include.errno
     libc.include.signal
@@ -67,8 +63,6 @@
     unistd-integration-tests
   SRCS
     execv_test.cpp
-  STARTUP
-    libc.startup.linux.crt1
   DEPENDS
     libc_execv_test_normal_exit
     libc_execv_test_signal_exit
@@ -86,8 +80,6 @@
     unistd-integration-tests
   SRCS
     execve_test.cpp
-  STARTUP
-    libc.startup.linux.crt1
   DEPENDS
     libc_execv_test_normal_exit
     libc_execv_test_signal_exit
diff --git a/libc/test/integration/startup/linux/CMakeLists.txt b/libc/test/integration/startup/linux/CMakeLists.txt
--- a/libc/test/integration/startup/linux/CMakeLists.txt
+++ b/libc/test/integration/startup/linux/CMakeLists.txt
@@ -9,8 +9,6 @@
 add_integration_test(
   startup_args_test
   SUITE libc-startup-tests
-  STARTUP
-    libc.startup.linux.crt1
   SRCS
     args_test.cpp
   ARGS
@@ -23,8 +21,6 @@
 add_integration_test(
   startup_no_envp_test
   SUITE libc-startup-tests
-  STARTUP
-    libc.startup.linux.crt1
   SRCS
     main_without_envp.cpp
 )
@@ -32,8 +28,6 @@
 add_integration_test(
   startup_no_args_test
   SUITE libc-startup-tests
-  STARTUP
-    libc.startup.linux.crt1
   SRCS
     main_without_args.cpp
 )
@@ -41,8 +35,6 @@
 add_integration_test(
   startup_tls_test
   SUITE libc-startup-tests
-  STARTUP
-    libc.startup.linux.crt1
   SRCS
     tls_test.cpp
   DEPENDS
@@ -55,8 +47,6 @@
 add_integration_test(
   init_fini_array_test
   SUITE libc-startup-tests
-  STARTUP
-    libc.startup.linux.crt1
   SRCS
     init_fini_array_test.cpp
 )