diff --git a/configure b/configure
index 2a87d109240bddc8f7ccafe9286c42527e9d3046..dab70385346e6452aab28f3264ca0beb3eefb4d0 100755
--- a/configure
+++ b/configure
@@ -13249,6 +13249,10 @@ fi
 
 fi
 
+if test -z $ac_header_dirent -o "$ac_header_dirent" = "no"; then
+  as_fn_error $? "*** Could not find dirent header that defines 'DIR'." "$LINENO" 5
+fi
+
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for ANSI C header files" >&5
 $as_echo_n "checking for ANSI C header files... " >&6; }
 if ${ac_cv_header_stdc+:} false; then :
@@ -13361,6 +13365,10 @@ $as_echo "#define STDC_HEADERS 1" >>confdefs.h
 
 fi
 
+if test "$ac_cv_header_stdc" != "yes"; then
+  as_fn_error $? "*** ANSI C header files not found." "$LINENO" 5
+fi
+
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for sys/wait.h that is POSIX.1 compatible" >&5
 $as_echo_n "checking for sys/wait.h that is POSIX.1 compatible... " >&6; }
 if ${ac_cv_header_sys_wait_h+:} false; then :
@@ -13402,7 +13410,38 @@ $as_echo "#define HAVE_SYS_WAIT_H 1" >>confdefs.h
 
 fi
 
-for ac_header in arpa/inet.h fcntl.h inttypes.h libintl.h limits.h locale.h malloc.h netdb.h netinet/in.h stddef.h stdint.h stdlib.h string.h strings.h sys/event.h sys/file.h sys/ioctl.h sys/param.h sys/socket.h sys/time.h syslog.h termios.h unistd.h utime.h arpa/nameser.h sys/io.h
+if test "$ac_cv_header_sys_wait_h" != "yes"; then
+  as_fn_error $? "*** POSIX.1 compatible sys/wait.h is required." "$LINENO" 5
+fi
+
+# Check for headers that are unconditionally required on all platforms.  Do not use
+# this to check for headers that are only needed by modules.
+for ac_header in  \
+  arpa/nameser.h assert.h ctype.h dlfcn.h errno.h fcntl.h float.h grp.h \
+  inttypes.h limits.h locale.h math.h pwd.h netinet/in.h regex.h resolv.h \
+  sched.h stdarg.h stdint.h stdio.h stdlib.h string.h syslog.h \
+  sys/file.h sys/ioctl.h sys/param.h sys/resource.h sys/socket.h sys/stat.h \
+  sys/time.h sys/types.h sys/un.h \
+  termios.h time.h unistd.h \
+
+do :
+  as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
+ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default"
+if eval test \"x\$"$as_ac_Header"\" = x"yes"; then :
+  cat >>confdefs.h <<_ACEOF
+#define `$as_echo "HAVE_$ac_header" | $as_tr_cpp` 1
+_ACEOF
+
+else
+
+  as_fn_error $? "*** A required header was not found." "$LINENO" 5
+
+fi
+
+done
+
+
+for ac_header in arpa/inet.h libintl.h malloc.h netdb.h stddef.h strings.h sys/event.h utime.h
 do :
   as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
 ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default"
diff --git a/configure.ac b/configure.ac
index d04d369022b0c439b55690c4070aa9bbed41ce79..d8a567fa62202d4e43c0efa739881236793afd7f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -589,9 +589,34 @@ AST_EXT_LIB_SETUP([ZLIB], [zlib compression], [z])
 
 AC_FUNC_ALLOCA
 AC_HEADER_DIRENT
+if test -z $ac_header_dirent -o "$ac_header_dirent" = "no"; then
+  AC_MSG_ERROR([*** Could not find dirent header that defines 'DIR'.])
+fi
+
 AC_HEADER_STDC
+if test "$ac_cv_header_stdc" != "yes"; then
+  AC_MSG_ERROR([*** ANSI C header files not found.])
+fi
+
 AC_HEADER_SYS_WAIT
-AC_CHECK_HEADERS([arpa/inet.h fcntl.h inttypes.h libintl.h limits.h locale.h malloc.h netdb.h netinet/in.h stddef.h stdint.h stdlib.h string.h strings.h sys/event.h sys/file.h sys/ioctl.h sys/param.h sys/socket.h sys/time.h syslog.h termios.h unistd.h utime.h arpa/nameser.h sys/io.h])
+if test "$ac_cv_header_sys_wait_h" != "yes"; then
+  AC_MSG_ERROR([*** POSIX.1 compatible sys/wait.h is required.])
+fi
+
+# Check for headers that are unconditionally required on all platforms.  Do not use
+# this to check for headers that are only needed by modules.
+AC_CHECK_HEADERS([ \
+  arpa/nameser.h assert.h ctype.h dlfcn.h errno.h fcntl.h float.h grp.h \
+  inttypes.h limits.h locale.h math.h pwd.h netinet/in.h regex.h resolv.h \
+  sched.h stdarg.h stdint.h stdio.h stdlib.h string.h syslog.h \
+  sys/file.h sys/ioctl.h sys/param.h sys/resource.h sys/socket.h sys/stat.h \
+  sys/time.h sys/types.h sys/un.h \
+  termios.h time.h unistd.h \
+], [], [
+  AC_MSG_ERROR([*** A required header was not found.])
+])
+
+AC_CHECK_HEADERS([arpa/inet.h libintl.h malloc.h netdb.h stddef.h strings.h sys/event.h utime.h])
 
 # Any one of these packages support a mandatory requirement, so we want to check on them as early as possible.
 AST_EXT_LIB_CHECK([TERMCAP], [termcap], [tgetent], [])
diff --git a/include/asterisk.h b/include/asterisk.h
index dc530dfd41a38e9441eae02e1c9d21602fb9553e..899438b0eef58845fa71602b19ba509854307e99 100644
--- a/include/asterisk.h
+++ b/include/asterisk.h
@@ -19,13 +19,12 @@
 #define _ASTERISK_H
 
 #include "asterisk/autoconfig.h"
+#include "asterisk/compat.h"
 
 #if !defined(NO_MALLOC_DEBUG) && !defined(STANDALONE) && !defined(STANDALONE2) && defined(MALLOC_DEBUG)
 #include "asterisk/astmm.h"
 #endif
 
-#include "asterisk/compat.h"
-
 /* Default to allowing the umask or filesystem ACLs to determine actual file
  * creation permissions
  */
@@ -54,8 +53,6 @@
 
 #if defined(DEBUG_FD_LEAKS) && !defined(STANDALONE) && !defined(STANDALONE2) && !defined(STANDALONE_AEL)
 /* These includes are all about ordering */
-#include <stdio.h>
-#include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/socket.h>
 #include <fcntl.h>
diff --git a/include/asterisk/astmm.h b/include/asterisk/astmm.h
index e129dc034a9a769b966de46d94027b6945984924..06300c861bf451f4e5c01bf476e277ba2e7e2078 100644
--- a/include/asterisk/astmm.h
+++ b/include/asterisk/astmm.h
@@ -30,21 +30,10 @@ extern "C" {
 
 #ifndef _ASTERISK_ASTMM_H
 #define _ASTERISK_ASTMM_H
-/* IWYU pragma: private, include "asterisk/utils.h" */
-
-#ifndef STANDALONE
+/* IWYU pragma: private, include "asterisk.h" */
 
 #define __AST_DEBUG_MALLOC
 
-#include "asterisk.h"
-
-/* Include these now to prevent them from being needed later */
-#include <sys/types.h>
-#include <stdlib.h>
-#include <string.h>
-#include <stdio.h>
-#include <stdarg.h>
-
 void *ast_std_malloc(size_t size);
 void *ast_std_calloc(size_t nmemb, size_t size);
 void *ast_std_realloc(void *ptr, size_t size);
@@ -179,8 +168,6 @@ void __ast_mm_init_phase_2(void);
 #define ast_free(a) \
 	__ast_free(a,__FILE__, __LINE__, __PRETTY_FUNCTION__)
 
-#endif /* !STANDALONE */
-
 #else
 #error "NEVER INCLUDE astmm.h DIRECTLY!!"
 #endif /* _ASTERISK_ASTMM_H */
diff --git a/include/asterisk/autoconfig.h.in b/include/asterisk/autoconfig.h.in
index 5446b010cb7a6341029c7aaa0488d39f0796197d..5f8a9d37c823e4a8735af671a70871e0e27c4f94 100644
--- a/include/asterisk/autoconfig.h.in
+++ b/include/asterisk/autoconfig.h.in
@@ -62,6 +62,9 @@
 /* Define to 1 if you have the `asprintf' function. */
 #undef HAVE_ASPRINTF
 
+/* Define to 1 if you have the <assert.h> header file. */
+#undef HAVE_ASSERT_H
+
 /* Define to 1 if you have the `atan' function. */
 #undef HAVE_ATAN
 
@@ -170,6 +173,9 @@
 /* Define to 1 if you have the 'crypt_r' function. */
 #undef HAVE_CRYPT_R
 
+/* Define to 1 if you have the <ctype.h> header file. */
+#undef HAVE_CTYPE_H
+
 /* Define to 1 if you have a functional curl library. */
 #undef HAVE_CURL
 
@@ -198,6 +204,9 @@
 /* Define to 1 if your system has the dladdr() GNU extension */
 #undef HAVE_DLADDR
 
+/* Define to 1 if you have the <dlfcn.h> header file. */
+#undef HAVE_DLFCN_H
+
 /* Define to 1 if you don't have `vprintf' but do have `_doprnt.' */
 #undef HAVE_DOPRNT
 
@@ -210,6 +219,9 @@
 /* Define to 1 if you have the `endpwent' function. */
 #undef HAVE_ENDPWENT
 
+/* Define to 1 if you have the <errno.h> header file. */
+#undef HAVE_ERRNO_H
+
 /* Define to 1 if you have the `euidaccess' function. */
 #undef HAVE_EUIDACCESS
 
@@ -243,6 +255,9 @@
 /* Define to 1 if you have the LIBFFTW3 library. */
 #undef HAVE_FFTW3
 
+/* Define to 1 if you have the <float.h> header file. */
+#undef HAVE_FLOAT_H
+
 /* Define to 1 if you have the `floor' function. */
 #undef HAVE_FLOOR
 
@@ -312,6 +327,9 @@
 /* Define if your system has the GMIME libraries. */
 #undef HAVE_GMIME
 
+/* Define to 1 if you have the <grp.h> header file. */
+#undef HAVE_GRP_H
+
 /* Define to indicate the GSM library */
 #undef HAVE_GSM
 
@@ -461,6 +479,9 @@
 /* Define to 1 if you have the <malloc.h> header file. */
 #undef HAVE_MALLOC_H
 
+/* Define to 1 if you have the <math.h> header file. */
+#undef HAVE_MATH_H
+
 /* Define to 1 if you have the `memchr' function. */
 #undef HAVE_MEMCHR
 
@@ -756,6 +777,9 @@
 /* Define to 1 if you have the `putenv' function. */
 #undef HAVE_PUTENV
 
+/* Define to 1 if you have the <pwd.h> header file. */
+#undef HAVE_PWD_H
+
 /* Define if your system has the PWLib libraries. */
 #undef HAVE_PWLIB
 
@@ -768,6 +792,9 @@
 /* Define to 1 if you have the `regcomp' function. */
 #undef HAVE_REGCOMP
 
+/* Define to 1 if you have the <regex.h> header file. */
+#undef HAVE_REGEX_H
+
 /* Define to 1 if you have the `remainder' function. */
 #undef HAVE_REMAINDER
 
@@ -777,6 +804,9 @@
 /* Define to 1 if you have the LIBRESAMPLE library. */
 #undef HAVE_RESAMPLE
 
+/* Define to 1 if you have the <resolv.h> header file. */
+#undef HAVE_RESOLV_H
+
 /* Define to 1 if your system has the close resolver function. */
 #undef HAVE_RES_CLOSE
 
@@ -813,6 +843,9 @@
 /* Define to 1 if your system has /sbin/launchd. */
 #undef HAVE_SBIN_LAUNCHD
 
+/* Define to 1 if you have the <sched.h> header file. */
+#undef HAVE_SCHED_H
+
 /* Define if your system has the SDL libraries. */
 #undef HAVE_SDL
 
@@ -893,6 +926,9 @@
    zero-length file name argument. */
 #undef HAVE_STAT_EMPTY_STRING_BUG
 
+/* Define to 1 if you have the <stdarg.h> header file. */
+#undef HAVE_STDARG_H
+
 /* Define to 1 if stdbool.h conforms to C99. */
 #undef HAVE_STDBOOL_H
 
@@ -902,6 +938,9 @@
 /* Define to 1 if you have the <stdint.h> header file. */
 #undef HAVE_STDINT_H
 
+/* Define to 1 if you have the <stdio.h> header file. */
+#undef HAVE_STDIO_H
+
 /* Define to 1 if you have the <stdlib.h> header file. */
 #undef HAVE_STDLIB_H
 
@@ -1070,9 +1109,6 @@
 /* Define to 1 if you have the <sys/ioctl.h> header file. */
 #undef HAVE_SYS_IOCTL_H
 
-/* Define to 1 if you have the <sys/io.h> header file. */
-#undef HAVE_SYS_IO_H
-
 /* Define to 1 if you have the <sys/ndir.h> header file, and it defines `DIR'.
    */
 #undef HAVE_SYS_NDIR_H
@@ -1083,6 +1119,9 @@
 /* Define to 1 if your system has working sys/poll.h */
 #undef HAVE_SYS_POLL_H
 
+/* Define to 1 if you have the <sys/resource.h> header file. */
+#undef HAVE_SYS_RESOURCE_H
+
 /* Define to 1 if you have the <sys/select.h> header file. */
 #undef HAVE_SYS_SELECT_H
 
@@ -1101,6 +1140,9 @@
 /* Define to 1 if you have the <sys/types.h> header file. */
 #undef HAVE_SYS_TYPES_H
 
+/* Define to 1 if you have the <sys/un.h> header file. */
+#undef HAVE_SYS_UN_H
+
 /* Define to 1 if you have <sys/wait.h> that is POSIX.1 compatible. */
 #undef HAVE_SYS_WAIT_H
 
@@ -1122,6 +1164,9 @@
 /* Define to 1 if your system defines timersub. */
 #undef HAVE_TIMERSUB
 
+/* Define to 1 if you have the <time.h> header file. */
+#undef HAVE_TIME_H
+
 /* Define to 1 if you have the Term Info library. */
 #undef HAVE_TINFO
 
diff --git a/include/asterisk/compat.h b/include/asterisk/compat.h
index 252ce914a276e5fc94f3d699ece11fd057e2443e..88f88cf8bb409a69842e74b4f69225426da71246 100644
--- a/include/asterisk/compat.h
+++ b/include/asterisk/compat.h
@@ -27,35 +27,18 @@
 #define	__STDC_VERSION__ 0
 #endif
 
-#ifdef HAVE_INTTYPES_H
 #include <inttypes.h>
-#endif
-
-#ifdef HAVE_LIMITS_H
 #include <limits.h>
-#endif
-
-#ifdef HAVE_UNISTD_H
 #include <unistd.h>
-#endif
 
 #ifdef HAVE_STDDEF_H
 #include <stddef.h>
 #endif
 
-#ifdef HAVE_STDINT_H
 #include <stdint.h>
-#endif
-
-#ifdef HAVE_SYS_TYPES_H
 #include <sys/types.h>
-#endif
-
 #include <stdarg.h>
-
-#ifdef HAVE_STDLIB_H
 #include <stdlib.h>
-#endif
 
 #ifdef HAVE_ALLOCA_H
 #include <alloca.h>    /* not necessarily present - could be in stdlib */
@@ -65,9 +48,7 @@
 
 #include <stdio.h>	/* this is always present */
 
-#ifdef HAVE_STRING_H
 #include <string.h>
-#endif
 
 #ifndef AST_POLL_COMPAT
 #include <poll.h>
@@ -158,7 +139,6 @@ void timersub(struct timeval *tvend, struct timeval *tvstart, struct timeval *tv
 
 #include <alloca.h>
 #include <strings.h>
-#include <string.h>
 #include <pthread.h>
 #include <sys/stat.h>
 #include <signal.h>