diff --git a/include/mbedtls/hmac_drbg.h b/include/mbedtls/hmac_drbg.h
index 2608de8..3bc675e 100644
--- a/include/mbedtls/hmac_drbg.h
+++ b/include/mbedtls/hmac_drbg.h
@@ -74,7 +74,7 @@
 /**
  * HMAC_DRBG context.
  */
-typedef struct
+typedef struct mbedtls_hmac_drbg_context
 {
     /* Working state: the key K is not stored explicitely,
      * but is implied by the HMAC context */