diff --git a/build/cmake/setup.cmake b/build/cmake/setup.cmake
index 45097e02d9..d294178203 100644
--- a/build/cmake/setup.cmake
+++ b/build/cmake/setup.cmake
@@ -646,15 +646,8 @@ if(wxUSE_XLOCALE)
     set(CMAKE_EXTRA_INCLUDE_FILES)
 endif()
 
-# Check size and availability of various types
-set(SYSTYPES
-    pid_t size_t
-    wchar_t int long short
-    gid_t uid_t
-    )
-if(NOT MSVC)
-    list(APPEND SYSTYPES mode_t off_t)
-endif()
+# Check sizes of various types
+set(SYSTYPES size_t wchar_t int long short)
 
 foreach(SYSTYPE ${SYSTYPES})
     string(TOUPPER ${SYSTYPE} SYSTYPE_UPPER)
diff --git a/build/cmake/setup.h.in b/build/cmake/setup.h.in
index b400d2eda9..d91c0811e2 100644
--- a/build/cmake/setup.h.in
+++ b/build/cmake/setup.h.in
@@ -17,21 +17,6 @@
 /* the installation location prefix from configure */
 #cmakedefine wxINSTALL_PREFIX "@wxINSTALL_PREFIX@"
 
-/* Define to `int' if <sys/types.h> doesn't define.  */
-#cmakedefine gid_t int
-
-/* Define to `int' if <sys/types.h> doesn't define.  */
-#cmakedefine mode_t int
-
-/* Define to `long' if <sys/types.h> doesn't define.  */
-#cmakedefine off_t long
-
-/* Define to `int' if <sys/types.h> doesn't define.  */
-#cmakedefine pid_t int
-
-/* Define to `unsigned' if <sys/types.h> doesn't define.  */
-#cmakedefine size_t unsigned
-
 /* Define if ssize_t type is available.  */
 #cmakedefine HAVE_SSIZE_T
 
@@ -43,9 +28,6 @@
 #cmakedefine _GNU_SOURCE 1
 #endif
 
-/* Define to `int' if <sys/types.h> doesn't define.  */
-#cmakedefine uid_t int
-
 /* Define if your processor stores words with the most significant
    byte first (like Motorola and SPARC, unlike Intel and VAX).  */
 #cmakedefine WORDS_BIGENDIAN 1
diff --git a/configure b/configure
index 107a4e5fd1..e76a56a6e1 100755
--- a/configure
+++ b/configure
@@ -29735,51 +29735,6 @@ WX_LIBRARY_BASENAME_GUI="wx_${TOOLKIT_DIR}${TOOLKIT_VERSION}${WIDGET_SET}${lib_u
 
 
 
-ac_fn_c_check_type "$LINENO" "mode_t" "ac_cv_type_mode_t" "$ac_includes_default"
-if test "x$ac_cv_type_mode_t" = xyes; then :
-
-else
-
-cat >>confdefs.h <<_ACEOF
-#define mode_t int
-_ACEOF
-
-fi
-
-ac_fn_c_check_type "$LINENO" "off_t" "ac_cv_type_off_t" "$ac_includes_default"
-if test "x$ac_cv_type_off_t" = xyes; then :
-
-else
-
-cat >>confdefs.h <<_ACEOF
-#define off_t long int
-_ACEOF
-
-fi
-
-ac_fn_c_check_type "$LINENO" "pid_t" "ac_cv_type_pid_t" "$ac_includes_default"
-if test "x$ac_cv_type_pid_t" = xyes; then :
-
-else
-
-cat >>confdefs.h <<_ACEOF
-#define pid_t int
-_ACEOF
-
-fi
-
-ac_fn_c_check_type "$LINENO" "size_t" "ac_cv_type_size_t" "$ac_includes_default"
-if test "x$ac_cv_type_size_t" = xyes; then :
-
-else
-
-cat >>confdefs.h <<_ACEOF
-#define size_t unsigned int
-_ACEOF
-
-fi
-
-
 ac_fn_c_check_type "$LINENO" "ssize_t" "ac_cv_type_ssize_t" "$ac_includes_default"
 if test "x$ac_cv_type_ssize_t" = xyes; then :
 
diff --git a/configure.in b/configure.in
index 57a7ba4610..12cae2fd01 100644
--- a/configure.in
+++ b/configure.in
@@ -4084,15 +4084,6 @@ dnl ---------------------------------------------------------------------------
 dnl Checks for typedefs
 dnl ---------------------------------------------------------------------------
 
-dnl   defines mode_t if not already defined
-AC_TYPE_MODE_T
-dnl   defines off_t if not already defined
-AC_TYPE_OFF_T
-dnl   defines pid_t if not already defined
-AC_TYPE_PID_T
-dnl   defines size_t if not already defined
-AC_TYPE_SIZE_T
-
 dnl sets HAVE_SSIZE_T if ssize_t is defined
 AC_CHECK_TYPES(ssize_t)
 
diff --git a/setup.h.in b/setup.h.in
index 9ca552a4ce..75c02fb407 100644
--- a/setup.h.in
+++ b/setup.h.in
@@ -17,21 +17,6 @@
 /* the installation location prefix from configure */
 #undef wxINSTALL_PREFIX
 
-/* Define to `int' if <sys/types.h> doesn't define.  */
-#undef gid_t
-
-/* Define to `int' if <sys/types.h> doesn't define.  */
-#undef mode_t
-
-/* Define to `long' if <sys/types.h> doesn't define.  */
-#undef off_t
-
-/* Define to `int' if <sys/types.h> doesn't define.  */
-#undef pid_t
-
-/* Define to `unsigned' if <sys/types.h> doesn't define.  */
-#undef size_t
-
 /* Define if ssize_t type is available.  */
 #undef HAVE_SSIZE_T
 
@@ -43,9 +28,6 @@
 #undef _GNU_SOURCE
 #endif
 
-/* Define to `int' if <sys/types.h> doesn't define.  */
-#undef uid_t
-
 /* Define if your processor stores words with the most significant
    byte first (like Motorola and SPARC, unlike Intel and VAX).  */
 #undef WORDS_BIGENDIAN
diff --git a/setup.h_vms b/setup.h_vms
index 261a3ea2c6..aa63876e8e 100644
--- a/setup.h_vms
+++ b/setup.h_vms
@@ -36,30 +36,12 @@
 /* Define this to get extra features from GNU libc. */
 #undef _GNU_SOURCE
 
-/* Define to `int' if <sys/types.h> doesn't define.  */
-#undef gid_t
-
-/* Define to `int' if <sys/types.h> doesn't define.  */
-#undef mode_t
-
-/* Define to `long' if <sys/types.h> doesn't define.  */
-#undef off_t
-
-/* Define to `int' if <sys/types.h> doesn't define.  */
-#undef pid_t
-
-/* Define to `unsigned' if <sys/types.h> doesn't define.  */
-#undef size_t
-
 /* Define if ssize_t type is available.  */
 #define HAVE_SSIZE_T 1
 
 /* Define if you have the ANSI C header files.  */
 #define STDC_HEADERS 1
 
-/* Define to `int' if <sys/types.h> doesn't define.  */
-#undef uid_t
-
 /* Define if your processor stores words with the most significant
    byte first (like Motorola and SPARC, unlike Intel and VAX).  */
 #undef WORDS_BIGENDIAN