diff --git a/ev_internal.h b/ev_internal.h
index 1b8282a..a265945 100644
--- a/ev_internal.h
+++ b/ev_internal.h
@@ -1,15 +1,17 @@
 #ifndef EV_HEADERS_INTERNAL_H
 #define EV_HEADERS_INTERNAL_H
 
-typedef signed char   i8;
-typedef short int     i16;
-typedef int           i32;
-typedef long long int i64;
+#include <stdint.h>
 
-typedef unsigned char          u8;
-typedef unsigned short int     u16;
-typedef unsigned int           u32;
-typedef unsigned long long int u64;
+typedef int8_t  i8;
+typedef int16_t i16;
+typedef int32_t i32;
+typedef int64_t i64;
+
+typedef uint8_t  u8;
+typedef uint16_t u16;
+typedef uint32_t u32;
+typedef uint64_t u64;
 
 typedef float  f32;
 typedef double f64;