diff --git a/interpreters/python/Makefile b/interpreters/python/Makefile
index 8f1a510e0..3f5f878ac 100644
--- a/interpreters/python/Makefile
+++ b/interpreters/python/Makefile
@@ -114,7 +114,7 @@ ifeq ($(CONFIG_ARCH_HAVE_FORK),y)
 else
 	@echo "export ac_cv_func_fork=\"no\"" >> $@
 endif
-ifneq ($(CONFIG_ARCH_HAVE_VFORK)$(CONFIG_ARCH_HAVE_FORK),)
+ifeq ($(CONFIG_ARCH_HAVE_VFORK),y)
 	@echo "export ac_cv_func_vfork=\"yes\"" >> $@
 else
 	@echo "export ac_cv_func_vfork=\"no\"" >> $@
diff --git a/netutils/libwebsockets/lws_config_private.h b/netutils/libwebsockets/lws_config_private.h
index cacf92f5f..057baf73b 100644
--- a/netutils/libwebsockets/lws_config_private.h
+++ b/netutils/libwebsockets/lws_config_private.h
@@ -119,7 +119,7 @@
 #endif
 
 /* Define to 1 if `vfork' works. */
-#if defined(CONFIG_ARCH_HAVE_VFORK) || defined(CONFIG_ARCH_HAVE_FORK)
+#ifdef CONFIG_ARCH_HAVE_VFORK
 #define LWS_HAVE_WORKING_VFORK
 #endif
 
diff --git a/testing/drivers/nand_sim/Kconfig b/testing/drivers/nand_sim/Kconfig
index 4baa4425e..008446a89 100644
--- a/testing/drivers/nand_sim/Kconfig
+++ b/testing/drivers/nand_sim/Kconfig
@@ -5,8 +5,7 @@
 
 config TESTING_NAND_SIM
 	boolean "NAND Flash Simulator"
-	depends on MTD_NAND_RAM && ENABLE_ALL_SIGNALS
-	depends on TASK_FORK || (ARCH_HAVE_FORK && !ARCH_HAVE_TASK_FORK)
+	depends on MTD_NAND_RAM && ENABLE_ALL_SIGNALS && TASK_FORK
 	default n
 	---help---
 		Enable the NAND Flash Simulator device.
diff --git a/testing/drivers/nand_sim/nand_sim_main.c b/testing/drivers/nand_sim/nand_sim_main.c
index 90597faa4..c45df4af8 100644
--- a/testing/drivers/nand_sim/nand_sim_main.c
+++ b/testing/drivers/nand_sim/nand_sim_main.c
@@ -143,14 +143,9 @@ int main(int argc, FAR char *argv[])
   pid_t pid;
 
   /* task_fork() rather than fork():  this wants a clone that outlives the
-   * caller and shares its memory.  The fallback below covers a nuttx that
-   * does not have task_fork() yet.
+   * caller and shares its memory.
    */
 
-#ifndef CONFIG_TASK_FORK
-#  define task_fork() fork()
-#endif
-
   pid = task_fork();
 
   if (pid > 0)
diff --git a/testing/fs/fdsantest/fdsantest_simple.c b/testing/fs/fdsantest/fdsantest_simple.c
index e5dc46817..114f0aeeb 100644
--- a/testing/fs/fdsantest/fdsantest_simple.c
+++ b/testing/fs/fdsantest/fdsantest_simple.c
@@ -96,7 +96,7 @@ static void test_case_overflow(void **state)
   assert_int_equal(open_count, close_count);
 }
 
-#if defined(CONFIG_ARCH_HAVE_VFORK) || defined(CONFIG_ARCH_HAVE_FORK)
+#ifdef CONFIG_ARCH_HAVE_VFORK
 static void test_case_vfork(void **state)
 {
   int fd = open("/dev/null", O_RDONLY);
@@ -131,7 +131,7 @@ int main(int argc, FAR char *argv[])
     cmocka_unit_test(test_case_unowned_tagged_close),
     cmocka_unit_test(test_case_owned_tagged_close),
     cmocka_unit_test(test_case_overflow),
-#if defined(CONFIG_ARCH_HAVE_VFORK) || defined(CONFIG_ARCH_HAVE_FORK)
+#ifdef CONFIG_ARCH_HAVE_VFORK
     cmocka_unit_test(test_case_vfork),
 #endif
   };
diff --git a/testing/ostest/CMakeLists.txt b/testing/ostest/CMakeLists.txt
index 76c1d25d0..ba1fcb23a 100644
--- a/testing/ostest/CMakeLists.txt
+++ b/testing/ostest/CMakeLists.txt
@@ -143,19 +143,15 @@ if(CONFIG_TESTING_OSTEST)
     endif()
   endif()
 
-  # See testing/ostest/ostest.h for the one transitional exception.
-
   if(CONFIG_TASK_FORK)
     list(APPEND SRCS task_fork.c)
-  elseif(CONFIG_ARCH_HAVE_FORK AND NOT CONFIG_ARCH_HAVE_TASK_FORK)
-    list(APPEND SRCS task_fork.c)
   endif()
 
   if(CONFIG_ARCH_HAVE_VFORK)
     list(APPEND SRCS vfork.c)
   endif()
 
-  if(CONFIG_ARCH_HAVE_FORK AND CONFIG_ARCH_HAVE_VFORK)
+  if(CONFIG_ARCH_HAVE_FORK)
     list(APPEND SRCS fork.c)
   endif()
 
diff --git a/testing/ostest/Makefile b/testing/ostest/Makefile
index ff89753f3..b35a3bbfb 100644
--- a/testing/ostest/Makefile
+++ b/testing/ostest/Makefile
@@ -144,17 +144,10 @@ CSRCS += sigev_thread.c
 endif
 endif
 
-# Each test is built where the primitive it tests exists.  See ostest.h for the
-# one transitional exception.
+# Each test is built where the primitive it tests exists.
 
 ifeq ($(CONFIG_TASK_FORK),y)
 CSRCS += task_fork.c
-else ifeq ($(CONFIG_ARCH_HAVE_TASK_FORK),)
-# A nuttx with no ARCH_HAVE_TASK_FORK at all is the pre-split one, where
-# fork() is task_fork().  This branch comes out with the split.
-ifeq ($(CONFIG_ARCH_HAVE_FORK),y)
-CSRCS += task_fork.c
-endif
 endif
 
 ifeq ($(CONFIG_ARCH_HAVE_VFORK),y)
@@ -162,10 +155,8 @@ CSRCS += vfork.c
 endif
 
 ifeq ($(CONFIG_ARCH_HAVE_FORK),y)
-ifeq ($(CONFIG_ARCH_HAVE_VFORK),y)
 CSRCS += fork.c
 endif
-endif
 
 ifeq ($(CONFIG_ARCH_SETJMP_H),y)
 CSRCS += setjmp.c
diff --git a/testing/ostest/ostest.h b/testing/ostest/ostest.h
index 77bf5e9f3..c8f41832a 100644
--- a/testing/ostest/ostest.h
+++ b/testing/ostest/ostest.h
@@ -282,55 +282,21 @@ void priority_inheritance(void);
 
 void sched_lock_test(void);
 
-/* The fork family **********************************************************/
-
-/* Until nuttx has the three separate primitives, ARCH_HAVE_FORK stands in
- * for task_fork():  today's fork() *is* task_fork(), so the test that has
- * always covered that primitive keeps running under its own name.  A nuttx
- * without ARCH_HAVE_TASK_FORK is the pre-split one, and only there does the
- * substitution apply -- once the split has landed, TASK_FORK says whether
- * task_fork() was built, and nothing stands in for it.
- *
- * vfork_test() and fork_test() deliberately have no such mapping.  They
- * check semantics a pre-split nuttx does not describe -- the parent
- * suspension and the private copy -- and ARCH_HAVE_VFORK is the evidence
- * that the split has landed.
- *
- * This block comes out with the split.
- */
-
-#if defined(CONFIG_TASK_FORK) || \
-    (defined(CONFIG_ARCH_HAVE_FORK) && !defined(CONFIG_ARCH_HAVE_TASK_FORK))
-#  define OSTEST_HAVE_TASK_FORK 1
-#endif
-
-#ifdef CONFIG_ARCH_HAVE_VFORK
-#  define OSTEST_HAVE_VFORK 1
-#endif
-
-#if defined(CONFIG_ARCH_HAVE_FORK) && defined(CONFIG_ARCH_HAVE_VFORK)
-#  define OSTEST_HAVE_FORK 1
-#endif
-
-#if defined(OSTEST_HAVE_TASK_FORK) && !defined(CONFIG_TASK_FORK)
-#  define task_fork() fork()
-#endif
-
 /* task_fork.c **************************************************************/
 
-#ifdef OSTEST_HAVE_TASK_FORK
+#ifdef CONFIG_TASK_FORK
 int task_fork_test(void);
 #endif
 
 /* vfork.c ******************************************************************/
 
-#ifdef OSTEST_HAVE_VFORK
+#ifdef CONFIG_ARCH_HAVE_VFORK
 int vfork_test(void);
 #endif
 
 /* fork.c *******************************************************************/
 
-#ifdef OSTEST_HAVE_FORK
+#ifdef CONFIG_ARCH_HAVE_FORK
 int fork_test(void);
 #endif
 
diff --git a/testing/ostest/ostest_main.c b/testing/ostest/ostest_main.c
index e717b291d..20aeba668 100644
--- a/testing/ostest/ostest_main.c
+++ b/testing/ostest/ostest_main.c
@@ -229,19 +229,19 @@ static int user_main(int argc, char *argv[])
    * reporting a failure -- better to learn that in seconds.
    */
 
-#ifdef OSTEST_HAVE_TASK_FORK
+#ifdef CONFIG_TASK_FORK
   printf("\nuser_main: task_fork() test\n");
   task_fork_test();
   check_test_memory_usage();
 #endif
 
-#ifdef OSTEST_HAVE_VFORK
+#ifdef CONFIG_ARCH_HAVE_VFORK
   printf("\nuser_main: vfork() test\n");
   vfork_test();
   check_test_memory_usage();
 #endif
 
-#ifdef OSTEST_HAVE_FORK
+#ifdef CONFIG_ARCH_HAVE_FORK
   printf("\nuser_main: fork() test\n");
   fork_test();
   check_test_memory_usage();
diff --git a/testing/ostest/task_fork.c b/testing/ostest/task_fork.c
index 2bd00ee76..2a66e289c 100644
--- a/testing/ostest/task_fork.c
+++ b/testing/ostest/task_fork.c
@@ -36,8 +36,6 @@
 
 #include "ostest.h"
 
-#ifdef OSTEST_HAVE_TASK_FORK
-
 /****************************************************************************
  * Private Data
  ****************************************************************************/
@@ -94,5 +92,3 @@ int task_fork_test(void)
   printf("task_fork_test: Child %d ran successfully\n", pid);
   return 0;
 }
-
-#endif /* OSTEST_HAVE_TASK_FORK */