diff --git a/include/mbedtls/bignum.h b/include/mbedtls/bignum.h
index 31383b1..732ecbe 100644
--- a/include/mbedtls/bignum.h
+++ b/include/mbedtls/bignum.h
@@ -177,7 +177,7 @@
 /**
  * \brief          MPI structure
  */
-typedef struct
+typedef struct mbedtls_mpi
 {
     int s;              /*!<  integer sign      */
     size_t n;           /*!<  total # of limbs  */