diff --git a/include/limits.h b/include/limits.h
index e20c036..9472dce 100755
--- a/include/limits.h
+++ b/include/limits.h
@@ -125,22 +125,38 @@
 
 #endif
 
-/* Numerical limits as defined in the ISO C standard */
-/* Shorts (Defined as 16-bit) */
+/* Numerical limits */
+/* Shorts (16-bit in both ISO and POSIX) */
 #define SHRT_MAX 32767
 #define SHRT_MIN -32767
 #define USHRT_MAX 65535
-/* Integers (Defined as 32-bit here) */
+/* Integers */
+#ifdef _POSIX_C_SOURCE
+/* If we're POSIX, int is 32-bit */
 #define WORD_BIT 32
 #define INT_MAX 2147483647
 #define INT_MIN -2147483648
 #define UINT_MAX 4294967295U
-/* Long ints (Defined as 64-bit) */
+#else
+/* If we're not POSIX, int is only 16-bit, for some reason. */
+#define INT_MAX 32767
+#define INT_MIN -32767
+#define UINT_MAX 65535U
+#endif
+/* Long ints */
+#ifdef _POSIX_C_SOURCE
+/* If we're POSIX, long is 64-bit */
 #define LONG_BIT 64
-#define LONG_MAX 9223372036854775807LL
-#define LONG_MIN -9223372036854775808LL
-#define ULONG_MAX 18446744073709551615ULL
-/* Long long ints (Also defined as 64-bit) */
+#define LONG_MAX 9223372036854775807L
+#define LONG_MIN -9223372036854775808L
+#define ULONG_MAX 18446744073709551615UL
+#else
+/* If we're not POSIX, long is only 32-bit */
+#define LONG_MAX 2147483647L
+#define LONG_MIN -2147483647L
+#define ULONG_MAX 4294967295UL
+#endif
+/* Long long ints (64-bit in both ISO and POSIX) */
 #define LLONG_MAX 9223372036854775807LL
 #define LLONG_MIN -9223372036854775808LL
 #define ULLONG_MAX 18446744073709551615ULL
@@ -156,10 +172,6 @@
 #define SCHAR_MAX 127
 #define SCHAR_MIN -128
 #define UCHAR_MAX 255
-#if defined(_POSIX_C_SOURCE) || defined(_XOPEN_SOURCE)
-#define MB_LEN_MAX 4
-#else
 #define MB_LEN_MAX 1
-#endif
 
 #endif /* ndef _FLC_LIMITS */