diff --git a/libc/include/llvm-libc-macros/limits-macros.h b/libc/include/llvm-libc-macros/limits-macros.h
--- a/libc/include/llvm-libc-macros/limits-macros.h
+++ b/libc/include/llvm-libc-macros/limits-macros.h
@@ -5,12 +5,6 @@
 #include <linux/limits.h>
 #endif
 
-#if __LP64__
-#define __LONG_MAX 0x7fffffffffffffffL
-#else
-#define __LONG_MAX 0x7fffffffL
-#endif // __LP64__
-
-#define LONG_MAX __LONG_MAX
+#define SSIZE_MAX __LONG_MAX__
 
 #endif // __LLVM_LIBC_MACROS_LIMITS_MACROS_H
diff --git a/libc/spec/posix.td b/libc/spec/posix.td
--- a/libc/spec/posix.td
+++ b/libc/spec/posix.td
@@ -228,6 +228,7 @@
   HeaderSpec Limits = HeaderSpec<
     "limits.h",
     [
+        Macro<"SSIZE_MAX">,
     ],
     [], // Types
     [], // Enumerations