diff --git a/include/polarssl/bignum.h b/include/polarssl/bignum.h
index b1c43b7..769e546 100644
--- a/include/polarssl/bignum.h
+++ b/include/polarssl/bignum.h
@@ -142,6 +142,7 @@
        typedef unsigned int t_udbl __attribute__((mode(TI)));
        #define POLARSSL_HAVE_UDBL
     #else
+       #define POLARSSL_HAVE_INT32
        typedef  int32_t t_sint;
        typedef uint32_t t_uint;
        #if ( defined(_MSC_VER) && defined(_M_IX86) )