diff --git a/kern/libkern/stdint.h b/kern/libkern/stdint.h
index aaced78..c88222e 100644
--- a/kern/libkern/stdint.h
+++ b/kern/libkern/stdint.h
@@ -24,6 +24,11 @@ typedef long  int64_t;
 typedef uint64_t size_t;
 typedef uint64_t uintptr_t;
 
+typedef int32_t  int_fast16_t;
+typedef int32_t  int_fast32_t;
+typedef uint32_t uint_fast16_t;
+typedef uint32_t uint_fast32_t;
+
 #define INT8_MIN  (-128)
 #define INT16_MIN (-32767 - 1)
 #define INT32_MIN (-2147483647 - 1)
@@ -39,4 +44,20 @@ typedef uint64_t uintptr_t;
 #define UINT32_MAX (4294967295U)
 #define UINT64_MAX (__UINT64_C(18446744073709551615))
 
+#define INT_FAST16_MIN INT32_MIN
+#define INT_FAST32_MIN INT32_MIN
+
+#define INT_FAST16_MAX INT32_MAX
+#define INT_FAST32_MAX INT32_MAX
+
+#define UINT_FAST16_MAX UINT32_MAX
+#define UINT_FAST32_MAX UINT32_MAX
+
+#define INTPTR_MIN  INT64_MIN
+#define INTPTR_MAX  INT64_MAX
+#define UINTPTR_MAX UINT64_MAX
+#define PTRDIFF_MIN INT64_MIN
+#define PTRDIFF_MAX INT64_MAX
+#define SIZE_MAX    UINT64_MAX
+
 #endif // STDINT_H