diff --git a/ChangeLog b/ChangeLog
index e3526ec..47ff14d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -9,6 +9,9 @@
 	 and X509parse.
 
 Bug fixes
+   * Prevented use of long long in bignum if 
+     POLARSSL_HAVE_LONGLONG not defined (found by Giles
+	 Bathgate).
    * Fixed incorrect handling of negative strings in
      mpi_read_string() (found by code coverage tests).
    * Fixed segfault on handling empty rsa_context in
diff --git a/include/polarssl/bignum.h b/include/polarssl/bignum.h
index 9c06a3f..8683a1e 100644
--- a/include/polarssl/bignum.h
+++ b/include/polarssl/bignum.h
@@ -54,7 +54,9 @@
         defined(__ia64__)  || defined(__alpha__)
     typedef unsigned int t_dbl __attribute__((mode(TI)));
     #else
-    typedef unsigned long long t_dbl;
+      #if defined(POLARSSL_HAVE_LONGLONG)
+      typedef unsigned long long t_dbl;
+      #endif
     #endif
   #endif
 #endif