diff --git a/libavcodec/common.h b/libavcodec/common.h
index 75ef127f24..7d5edb4a7d 100644
--- a/libavcodec/common.h
+++ b/libavcodec/common.h
@@ -125,13 +125,13 @@
 #endif
 
 #ifdef EMULATE_FAST_INT
-/* note that we don't emulate 64bit ints */
 typedef signed char int_fast8_t;
 typedef signed int  int_fast16_t;
 typedef signed int  int_fast32_t;
 typedef unsigned char uint_fast8_t;
 typedef unsigned int  uint_fast16_t;
 typedef unsigned int  uint_fast32_t;
+typedef uint64_t      uint_fast64_t;
 #endif
 
 #ifndef INT_BIT