diff --git a/libc/spec/spec.td b/libc/spec/spec.td
--- a/libc/spec/spec.td
+++ b/libc/spec/spec.td
@@ -61,7 +61,6 @@
 
 def WCharType : NamedType<"wchar_t">;
 def WIntType : NamedType<"wint_t">;
-def MBStateType : NamedType<"mbstate_t">;
 
 def LongDoublePtr : PtrType<LongDoubleType>;
 
diff --git a/libc/spec/stdc.td b/libc/spec/stdc.td
--- a/libc/spec/stdc.td
+++ b/libc/spec/stdc.td
@@ -1078,8 +1078,6 @@
         SizeTType,
         WIntType,
         WCharType,
-        MBStateType,
-        StructTmType,
       ],
       [], // Enumerations
       [