--- apps/speed.c
+++ apps/speed.c
@@ -99,6 +99,13 @@
 #endif
 #include <openssl/modes.h>
 
+/* fork() breaks AppleTVOS, WatchOS, AppleTVSimulator and WatchSimulator */
+/* Users should configure with -DNO_FORK */
+#if defined(NO_FORK)
+# undef HAVE_FORK
+# define HAVE_FORK 0
+#endif
+
 #ifndef HAVE_FORK
 # if defined(OPENSSL_SYS_VMS) || defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_VXWORKS)
 #  define HAVE_FORK 0
@@ -110,6 +117,7 @@
 #if HAVE_FORK
 # undef NO_FORK
 #else
+# undef NO_FORK
 # define NO_FORK
 #endif
 
--- apps/ocsp.c
+++ apps/ocsp.c
@@ -36,6 +36,13 @@
 # include <openssl/x509v3.h>
 # include <openssl/rand.h>
 
+/* fork() breaks AppleTVOS, WatchOS, AppleTVSimulator and WatchSimulator */
+/* Users should configure with -DNO_FORK */
+#if defined(NO_FORK)
+# undef HAVE_FORK
+# define HAVE_FORK 0
+#endif
+
 #ifndef HAVE_FORK
 # if defined(OPENSSL_SYS_VMS) || defined(OPENSSL_SYS_WINDOWS)
 #  define HAVE_FORK 0
@@ -47,6 +54,7 @@
 #if HAVE_FORK
 # undef NO_FORK
 #else
+# undef NO_FORK
 # define NO_FORK
 #endif