diff --git a/libc/limits.h b/libc/limits.h
index 6e0ce5d0688..cc222691823 100644
--- a/libc/limits.h
+++ b/libc/limits.h
@@ -12,22 +12,6 @@
 #define CHAR_MAX '\377'
 #endif
 
-#define SIZEOF_SHORT       __SIZEOF_SHORT__
-#define SIZEOF_INT         __SIZEOF_INT__
-#define SIZEOF_LONG        __SIZEOF_LONG__
-#define SIZEOF_LONG_LONG   __SIZEOF_LONG_LONG__
-#define SIZEOF_POINTER     __SIZEOF_POINTER__
-#define SIZEOF_PTRDIFF_T   __SIZEOF_PTRDIFF_T__
-#define SIZEOF_SIZE_T      __SIZEOF_SIZE_T__
-#define SIZEOF_WCHAR_T     __SIZEOF_WCHAR_T__
-#define SIZEOF_WINT_T      __SIZEOF_WINT_T__
-#define SIZEOF_FLOAT       __SIZEOF_FLOAT__
-#define SIZEOF_FLOAT128    __SIZEOF_FLOAT128__
-#define SIZEOF_DOUBLE      __SIZEOF_DOUBLE__
-#define SIZEOF_FLOAT80     __SIZEOF_FLOAT80__
-#define SIZEOF_LONG_DOUBLE __SIZEOF_LONG_DOUBLE__
-#define SIZEOF_INTMAX      __SIZEOF_INTMAX__
-
 #define SCHAR_MAX     __SCHAR_MAX__
 #define SHRT_MAX      __SHRT_MAX__
 #define INT_MAX       __INT_MAX__
diff --git a/tool/emacs/c.lang b/tool/emacs/c.lang
index 31bf0008130..f51c8ca607b 100644
--- a/tool/emacs/c.lang
+++ b/tool/emacs/c.lang
@@ -1705,21 +1705,6 @@ Keywords={
 "IMAGE_BASE_VIRTUAL",
 "IMAGE_BASE_REAL",
 "IMAGE_BASE_PHYSICAL",
-"SIZEOF_SHORT",
-"SIZEOF_INT",
-"SIZEOF_LONG",
-"SIZEOF_LONG_LONG",
-"SIZEOF_POINTER",
-"SIZEOF_PTRDIFF_T",
-"SIZEOF_SIZE_T",
-"SIZEOF_WCHAR_T",
-"SIZEOF_WINT_T",
-"SIZEOF_FLOAT",
-"SIZEOF_FLOAT128",
-"SIZEOF_DOUBLE",
-"SIZEOF_FLOAT80",
-"SIZEOF_LONG_DOUBLE",
-"SIZEOF_INTMAX",
 "SCHAR_MAX",
 "SHRT_MAX",
 "INT_MAX",
diff --git a/tool/emacs/cosmo-c-constants.el b/tool/emacs/cosmo-c-constants.el
index f5c1a8cd5a2..8a1b23029d2 100644
--- a/tool/emacs/cosmo-c-constants.el
+++ b/tool/emacs/cosmo-c-constants.el
@@ -22,21 +22,6 @@
   '("IMAGE_BASE_VIRTUAL"
     "IMAGE_BASE_REAL"
     "IMAGE_BASE_PHYSICAL"
-    "SIZEOF_SHORT"
-    "SIZEOF_INT"
-    "SIZEOF_LONG"
-    "SIZEOF_LONG_LONG"
-    "SIZEOF_POINTER"
-    "SIZEOF_PTRDIFF_T"
-    "SIZEOF_SIZE_T"
-    "SIZEOF_WCHAR_T"
-    "SIZEOF_WINT_T"
-    "SIZEOF_FLOAT"
-    "SIZEOF_FLOAT128"
-    "SIZEOF_DOUBLE"
-    "SIZEOF_FLOAT80"
-    "SIZEOF_LONG_DOUBLE"
-    "SIZEOF_INTMAX"
     "CHAR_MAX"
     "SCHAR_MAX"
     "SHRT_MAX"