diff --git a/racket/src/foreign/foreign.rktc b/racket/src/foreign/foreign.rktc
index fc30f8634e..228000f239 100755
--- a/racket/src/foreign/foreign.rktc
+++ b/racket/src/foreign/foreign.rktc
@@ -29,6 +29,9 @@ exec racket "$0" > `echo "$0" | sed 's/rktc$/c/'` "$0"
 }
 
 @@@IF{!defined(WINDOWS_DYNAMIC_LOAD) || defined(__MINGW32__)}{
+   typedef   signed char Tsint8;
+   typedef unsigned char Tuint8;
+
 # if SIZEOF_SHORT == 2
    typedef   signed short Tsint16;
    typedef unsigned short Tuint16;