diff --git a/config.h.meson b/config.h.meson
index 808586d0b5..22949b3964 100644
--- a/config.h.meson
+++ b/config.h.meson
@@ -132,15 +132,9 @@
 /* Define to 1 if you have the <dlfcn.h> header file. */
 #mesondefine HAVE_DLFCN_H
 
-/* Define to 1 if you have the `fgetpos' function. */
-#mesondefine HAVE_FGETPOS
-
 /* Define to 1 if fseeko (and presumably ftello) exists and is declared. */
 #mesondefine HAVE_FSEEKO
 
-/* Define to 1 if you have the `fsetpos' function. */
-#mesondefine HAVE_FSETPOS
-
 /* Define to 1 if you have the `ftello' function. */
 #mesondefine HAVE_FTELLO
 
@@ -205,9 +199,6 @@
 /* Define to 1 if you have the <poll.h> header file. */
 #mesondefine HAVE_POLL_H
 
-/* Define to 1 if you have the `posix_memalign' function. */
-#mesondefine HAVE_POSIX_MEMALIGN
-
 /* Have posix timers */
 #mesondefine HAVE_POSIX_TIMERS
 
diff --git a/configure.ac b/configure.ac
index 57cb69b582..66e51bfe1a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -658,12 +658,7 @@ AC_RUN_IFELSE([AC_LANG_SOURCE([[
   [broken_poll="no (cross compiling)"])
 AC_MSG_RESULT($broken_poll)
 
-dnl check for mmap()
-AC_FUNC_MMAP
-AM_CONDITIONAL(HAVE_MMAP, test "x$ac_cv_func_mmap_fixed_mapped" = "xyes")
-
-dnl check for posix_memalign(), getpagesize()
-AC_CHECK_FUNCS([posix_memalign])
+dnl check for getpagesize()
 AC_CHECK_FUNCS([getpagesize])
 
 dnl Check for POSIX timers
diff --git a/meson.build b/meson.build
index d8fae79e49..9571caaa48 100644
--- a/meson.build
+++ b/meson.build
@@ -147,8 +147,6 @@ check_functions = [
   'getrusage',
   'fseeko',
   'ftello',
-  'fsetpos',
-  'fgetpos',
   'poll',
   'pselect',
   'getpagesize',
@@ -167,17 +165,12 @@ foreach f : check_functions
   endif
 endforeach
 
-cdata.set('HAVE_MMAP', 1)
 if cc.has_function('localtime_r', prefix : '#include<time.h>')
   cdata.set('HAVE_LOCALTIME_R', 1)
   # Needed by libcheck
   cdata.set('HAVE_DECL_LOCALTIME_R', 1)
 endif
 
-if cc.has_function('posix_memalign', prefix : '#include<stdlib.h>')
-  cdata.set('HAVE_POSIX_MEMALIGN', 1)
-endif
-
 # We only want to use the __declspec(dllexport/import) dance in GST_EXPORT when
 # building with MSVC
 if cc.get_id() == 'msvc'