diff --git a/profiles/toolchain/64-default.h b/profiles/toolchain/64-default.h
index 098854a..d181917 100644
--- a/profiles/toolchain/64-default.h
+++ b/profiles/toolchain/64-default.h
@@ -1,24 +1,6 @@
 #ifndef PY_TOOLCHAIN_64_DEFAULT_H
 #define PY_TOOLCHAIN_64_DEFAULT_H
 
-#define SIZEOF_DOUBLE                   8
-#define SIZEOF_FLOAT                    4
-#define SIZEOF_FPOS_T                   16
-#define SIZEOF_INT                      4
-#define SIZEOF_LONG                     8
-#define SIZEOF_LONG_DOUBLE              16
-#define SIZEOF_LONG_LONG                8
-#define SIZEOF_OFF_T                    8
-#define SIZEOF_PID_T                    4
-#define SIZEOF_PTHREAD_T                8
-#define SIZEOF_SHORT                    2
-#define SIZEOF_SIZE_T                   8
-#define SIZEOF_TIME_T                   8
-#define SIZEOF_UINTPTR_T                8
-#define SIZEOF_VOID_P                   8
-#define SIZEOF_WCHAR_T                  4
-#define SIZEOF__BOOL                    1
-
 #define HAVE_GCC_ASM_FOR_X87            1
 #define HAVE_GCC_ASM_FOR_X64            1
 
diff --git a/project/config/cfgdefs.sh b/project/config/cfgdefs.sh
index ff48f02..560afa6 100644
--- a/project/config/cfgdefs.sh
+++ b/project/config/cfgdefs.sh
@@ -105,9 +105,48 @@ cfgdefs_perform_common_tests()
 	mb_cfgtest_headers='sys/sendfile.h'
 	cfgtest_interface_presence 'sendfile'
 
+	# size of system types
+	cfgtest_newline
+	cfgtest_comment 'size of system types'
+
+	cfgtest_type_size 'short'
+	cfgtest_type_size 'int'
+	cfgtest_type_size 'long'
+	cfgtest_type_size 'long long'
+	cfgtest_type_size 'float'
+	cfgtest_type_size 'double'
+	cfgtest_type_size 'long double'
+	cfgtest_type_size 'void *'
+
+	mb_cfgtest_headers='stdint.h'
+	cfgtest_type_size 'uintptr_t'
+
+	mb_cfgtest_headers='stdbool.h'
+	cfgtest_type_size '_Bool'
+
+	mb_cfgtest_headers='stddef.h'
+	cfgtest_type_size 'size_t'
+	cfgtest_type_size 'wchar_t'
+
+	mb_cfgtest_headers='unistd.h'
+	cfgtest_type_size 'pid_t'
+	cfgtest_type_size 'off_t'
+
+	mb_cfgtest_headers='time.h'
+	cfgtest_type_size 'time_t'
+
+	mb_cfgtest_headers='stdio.h'
+	cfgtest_type_size 'fpos_t'
+
+	mb_cfgtest_headers='pthread.h'
+	cfgtest_type_size 'pthread_t'
+
 	# getrandom: easier to simply test,
 	# than to test whether we need to test
 	# (and then test).
+	cfgtest_newline
+	cfgtest_comment 'getrandom'
+
 	mb_cfgtest_headers='sys/syscall.h'
 
 	if cfgtest_decl_presence 'SYS_getrandom'; then