diff --git a/Tools/CCode/Source/Common/CommonLib.c b/Tools/CCode/Source/Common/CommonLib.c
index 618abd89bb..4ae5542b8b 100644
--- a/Tools/CCode/Source/Common/CommonLib.c
+++ b/Tools/CCode/Source/Common/CommonLib.c
@@ -496,10 +496,10 @@ Returns:
 
 #ifdef __GNUC__
 
-size_t _filelength(FILE *file)
+size_t _filelength(int fd)
 {
   struct stat stat_buf;
-  fstat(fileno(file), &stat_buf);
+  fstat(fd, &stat_buf);
   return stat_buf.st_size;
 }
 
diff --git a/Tools/CCode/Source/Common/CommonLib.h b/Tools/CCode/Source/Common/CommonLib.h
index f6c29ef8a8..40d35356e7 100644
--- a/Tools/CCode/Source/Common/CommonLib.h
+++ b/Tools/CCode/Source/Common/CommonLib.h
@@ -130,7 +130,7 @@ PrintGuidToBuffer (
 #define _stricmp strcasecmp
 #define strnicmp strncasecmp
 #define strcmpi strcasecmp
-size_t _filelength(FILE *file);
+size_t _filelength(int fd);
 #ifndef __CYGWIN__
 char *strlwr(char *s);
 #endif